Another brilliant video, once my gas boiler dies I'll have to get you to come fit me an ASHP! My neighbour had one fitted by a cowboy and she has had no end of trouble really goes to show that the technology works, the key is a good tradesman. Keep up the good work.
You're a great example to installers of... anything tbh! You have a focus and an enthusiasm that is inspiring, love your work. I'd like you to reinstall my heat pump, I bet you'd find some over engineering in the system.
Another excellent video. We have basically the same system, installed in March of last year. In March this year we had the UFH pump and the upstairs radiator pump removed as they were no longer required. It’s great to see someone else working this out as well. Please keep up the great work.
@@UrbanPlumbers if I were to design a house now I would have underfloor downstairs, single Zone. Radiators upstairs with only balancing valves. It’s essentially how our house is running now. We are evening running it with the adaptive heat curve enable. Love it! The new version of the Vaillant app makes a big difference now as well. Keep up the great work.
Great description of how to have a simple install. Getting rid of those pumps will increase the COP a good deal to begin with. And great to see a female plumber. When it comes to mass installs as it will soon having ladies to talk through the system with older folks will make them happier to have one.
Wish I'd known about you earlier!! I had a heat pump installed last year, and the amount of pumps baffles me. (got 3 external pumps, one for upstairs rads, one for downtairs UFH and one for the system, and a LLH) for an average size 3 bed semi. Keeping it simple is almost always the answer.
Great video! we moved into a property which already had an ASHP in place feeding ufh and rads. It also has a buffer tank and extra circulators and we are currently talking with our local installer to have them removed. Already I have disconnected all the actuators to remove room zoning on the ufh. No idea what the scop is as it’s a ten year old heat pump. Your channel has been great to try and understand the essentials of heating system design.
Wow Simon so cool to see your work again, really showing its not that complicated to have a heat pump installed, simplify the system. I have myself audited many systems, that have been over engineered/pumped, removed those extra pumps them with good results.
lovely work on the job, was listening to Betatalk episode the other day in regards to the insulation and its nice to see it being put into practice! your episode on there was great too!
Excellent work! Here in Germany, unfortunately, many plumbers are afraid of installing the heat pump without a buffer. Absolute nonsense =) The heat pump can only work properly and efficiently if no buffer is installed and it works in the direct circuit. There is still a lot to learn here in Germany. Luckily I installed mine myself. Annual performance factor, measured externally with defrosts... 4.6 😊 (location bavaria)
@@UrbanPlumbers 5.3 is VERY good 👍😉 Here it is -10 to -15°C in winter.... sometimes -20°C, that reduces the work rate quite a bit. Nevertheless, heatpipes are definitely the future of heating 👍
@@energieundhobby Future maybe, but not quite yet for older houses, having a hated cylinder back is a big letdown, and it's too complicated, the plumbing should be one pump internal and one expansion vessel!?!
Hi Simon, now that the gov are increasing the grant to £7.5k I have decided that now is seems to be a good time to go ahead and have an air source heat pump system installed. I am with Octopus and they said that the expected cost to me should be below £3k including any rads, pipework etc (I upgraded my rad three years ago so am hoping my newer ones will be up to scratch. I also had a large unvented cylinder installed which is squeezed into my airing cupboard on the first floor. The boiler was replaced at the same time with a condensing Vailantboiler and it was repositioned to the garage). Octopus will be contacting me to arrange a survey to check out and go over what is needed. I have a small three bed detached house built in 1994 which I had cavity wall insultion pumped in two years ago and I have had a PV (4.8Kw) and battery (14.4kWh) system installed last year, so am hoping my running costs should be a lot lower. The problem I am anticipating is that my house when built was plumbed with microbore (8mm?) and so was wondering if you can comment on this and if it is still viable to have an air source system installed. Also would you be able to carry out my installation, either in conjunction with Octopus, or directly with me? I live in Old Coulsdon, in the southern part of the borough of Croydon. Looking forward to hearing from you. Thanks, Al
Recently helped a neighbour out with his heat pump hydronic design, because he couldn't find a plumber who knew how to size a heat pump and design the hydronic system. The lack of proper training is abysmal in the UK. You are the one exception, of course😂
yep, 95% are winging it. It is changing though thanks to Heat Geek, Kim's Northampton Heating Academy, and a few others. I spoke to Vaillant, and they will be bringing hydronic courses as well. The movement is slow but in the right direction.
Very well presented, knowledge is the key here. Getting to this level should be a basic thing for any heating engineer but like you mentioned need the resources to learn from..
Your knowledge & workmanship on the hydronic circuit is truly exceptional - but who does the owner call when it goes wrong? Is it the wet side or the refrigeration circuit that has failed? - my AC biased engineering team would have no issue diagnosing or repairing the refrigeration side of things, but would struggle (or not be interested) in the wet side. Likely to be vice versa for a plumber/mechanical engineer. Most air to water or ground source heat pumps that come my way have not been correctly designed/installed/commissioned - giving the technology a bad reputation. Unfortunately, engineers such as yourself are the exception….not the rule. Please keep up the good work & educational videos.
@@hvacdesignsolutions Show me a plumber that can do heat loss calcs & actually commission an UFH system properly (including controls/wiring) & I'll show you my arse! 🤣🤣
On the contrary. Engineer should be a reserved title like lawyer and architect. Proper university educated (or equiv) engineers do calculalations all the time and design complex equipment / systems. Problem is when some installers and 'fitters' start calling themselves engineers. Holland understands the difference and distinguishes between engineers and technicians. This guy clearly knows his stuff; the importance of calculations and simplifying the install.
@@JonPearson-mm1cd the use of engineer is no longer the preserve of the university educated person. In my time as an engineer I have experienced my French colleagues address me as Mr Engineer and London city types look down on me as if I had walked in with dirty coveralls on. In my mind an engineer is someone that takes the engineering approach and applies appropriate methodology and calculation to the task at hand with the appropriate insight and education whether self taught or formally taught - it is the method and tools that count. I hold two masters and one undergraduate degree however I am not a snob on the topic.
Great video, communicates the important issues very clearly. Why only one anti freeze valve on the return? I have only previously seen one on the flow and another on the return, an explanation wou;d be greatly appreciated.
Just a note on needing a second pump. 100mm spacing UFH works more efficiently than 150-200mm for low flow temperatures, but it may need to be 'microbore', ie. 8.6mm bore to make the tight bends. Check carefully the pressure loss on the longest loop and you could find an additional pump is required. As long at it's placed after the T off to the UFH, it won't interfere with the modulation of the main circulating pump.
If you use a floating UFH system like Variotherm (ie. not in a screed), that's microbore. It's an excellent system from Austria, no aluminium spreader plates, routed into Fermacell, so more thermal mass than similar XPS ones.
I have seen it mentioned a few time now that you don't put in zone to improve the efficiencies. How much will zoning impact the performance of the system? Is there any way to keep the bedrooms cooler than the living spaces without zoning?
@cillo2000 yes there is - TRVs or actuators to limit the temp without ability to activate the heat source. In practice you can do it just by adjusting flow
Fantastic install. Agree with the simplification, but doesn't this mean the max floor temp will be 40degC? Too hot for some floor coverings. Why no mixing valve on the UFH manifold to reduce the UFH temperature?
Syzmon that was absolutely excellent.👍 Can I just pick up on your design point of establish head loss of the index circuit and checking the pump curve to ensure it can overcome that. In this situation those calculations enabled you to make two pumps redundant and were able to use the units integral system pump. So, if the integral system pump had been too ‘small’ could you have fitted a larger one without encroaching on manufacturers warranty conditions? Thanks for sharing all this good stuff.😀👍
With such a large outdoor area, I'm amazed the customer did not go for a Ground Source Heat Pump? It appears the perfect property for it! ALSO, did you design the system to have radiators and UFH on identical flow temperatures?!?
Lovely video as usual! Question about UFH without zone valves or actuators..... did they rely on different spacings to acheive the different temp/ heat loss requirement in different rooms? Seems a high risk strategy to try and acheive that with one constant temp flow through the entire system....... Especially when those controls would be a tiny part of the budget. Keep up the great work, I love the more technical aspects of your videos!
Yes, it relies on good design and proper commissioning. You can actually adjust flow through different loops and also radiator circuits and match the mean water temperature to the heat loss of the room. This is not about saving money on installation by not having thermostats or actuators. This is about keeping as much of the system open as possible as it dramatically increases the system efficiency and lowers running costs.
@@UrbanPlumberssince I’d come to ask the same question… is there not a risk then of those various relative flow rates (through the different loops) shifting over time, and then without any active zone control, there would be hot/cold areas in he home? Also, am I right in thinking that there’s only heating in this design when there’s no hot water demand? If so, could this not be problematic? I’m all for the simplification btw - less points of failure, and I understand that maximum efficiency requires maximum flow, but I worry that any imbalance in the system further down the line could be problematic with active controls to keep everything in check.
@@rickwookie imbalance in the system is not really an issue with fully weather-compensated low-temperature systems as it is with high-temperature systems that are prone to overheating. I have loads of systems running like this with no major issues.
I keep being advised to fill the Heat Pump with anti freeze by the manufacturer including Vaillant with the addition cost of a heat exchanger unit so the whole system isn’t filled with anti freeze. I notice this isn’t something you ever do but I’m a little nervous about going against the manufacturers advice.
I'm inclined to use trace heating rather than anti-freeze. The trace heating only comes on where there is any actual risk of freezing, and keeping the external pipework short minimises the cost of installing and then running the trace heating.
Interesting to learn that the new heat pump can run the DHW to kill legionella but it is close to a COP of 1. Given that the immersion heater is 100% efficient and you will be without heating while the DHW is heating up to 60 deg C I can't see the advantage of getting the heat pump to run the legionella cycle.
thank you for watching. KISS definitely works with heat pumps. This is the trouble with the heating industry - everyone tries to overcomplicate things and invent solutions for nonexisting problems that cause real problems instead - if that makes sense.
I'm in the Netherlands and i cannot find anyone as good as you or the heat geeks! Are there any recommendations or do you give an online service for what to buy and to install in my situation?
The error code also indicated the fault was with the motor. I've had occasional successes sourcing motors from other suppliers than the original equipment manfacturer. If you can find the motor part number, you might be able to find it somewhere else.
Super cheap to keep it warm even with the old heat pump as it’s all UFH and a well insulated property. I think they said they used to pay £200 / month last winter. I will update running cost on this job this winter with a follow up video.
Great video - thanks. As a designer I wanted to run underfloor and radiators on one pump, but my calculations have shown that I'd need higher temperature for radiators than floor (though both low - eg 40 C radiators, 28 C floor) so have ended up with motorised mixing valve & pump for underfloor, all under heat pump control. I'd rather be on one pump but worry that either the rads will be too cold to do much, or the underfloor will overheat. I do like the absence of manifold actuators and have gone for manual adjusters for user to tweak rooms as required. Will you do an update in winter so we can see how it works in practice?
@@andrewmillwardwatford9410 it is not that simple Andrew. It varies from job to job. You can also fine-tune rads / UFH with a gate valve on a return from the rads. I got 5-6 of those types of jobs installed now, but need to wait for the winter to see how they perform and if they need any additional adjustments. Tommy Jones is trying an interesting by-pass / CCT concept on heat pumps, where UFH gets a lower temp than rads. He struggles with too much output from UFH on some of his jobs. My experience is the same - too much output from UFH most of the time and not enough from rads. Obviously much easier to do the same flow on the same DT - not as you would do on a gas boiler.
My 10 year old 3 bed semi has 10mm plastic pipework feeding all radiators. The main flow and return is under the 1st floor with 10mm pipe work dropping down to the ground floor rads behind the dry lined walls. My question is will all this pipe work have to be replaced.
I work in social housing as an electrician. Where i work now they are still fitting baxi assure boilers, i guess hoping hydrogen will take over from gas (it wont). I think eventually they will be forced to start fitting heat pumps in bulk. But there are many horror stories from social housing tenants of poorly installed and inefficient heat pumps, having been fitted by contractors with no real understanding of them. I really hope there is good training for the people who will end up fitting heat pumps in social housing or tenants will be pushed further into fuel poverty by botched installs.
Air-air and a direct unvented for the social housing stock. Easy on/off controls, people can only heat the rooms they need, and they cost sweet f-all… Air-water needs a different mindset and end user education.
Very interesting video, one thing that keeps me wondering is the Old evaporator had a very long pipe run to the house; advice by British Gas Daikin intaller says maximum 10m run to the hot water tank. can you please comment on allowed length of primary pipework bearing in mind if evaporator cannot be sited close to the house.
Almost any length is possible if it is calculated and sized correctly. You can have way more than 10m but it becomes expensive quickly due to the fact that pipework may have to be of a larger size and will require insulating or boxing or running in pre insulated pipe underground Look at split units if the evaporator needs to be sized further away
Excellent video again. I'm a home owner building my own home. Struggling to get someone to do overall design so teaching myself. I have UFH upstairs and down at 100 c/c spacing. High insulation and air tightness. High thermal mass. I'm happy that I have built the basics correctly so will only need a small pump to heat a large house at very low flow temps. The bit I'm struggling with is how best to integrate about 7m of solar thermal panels I had built into a south facing roof. Any pointers?
I have a log burner vented back boiler in my workshop that is connected inside the house to a heat exchanger on the return side of an unvented combi boiler heating circuit, it keeps the pressurised system separate and has its own sludge filter. You could do similar with your set up, its like a pre heater before the main heating source. if your using a new ASHP like the Valiant he's installed you probably would benefit more from selling the thermal panels and installing 400w PV panels/battery storage to power the whole system as long term you will have greater financial and green gains.
What courses do you recommend for getting into air source heat pumps? I'm a gad engineer and trying to move with the times. Don't want to be left behind lol
The company I'm working for are putting me on a heat pump design and installation PLUS putting me through F Gas. I love how simple these systems are (Like the old fashion heating systems really) - The thing I'm worried about is the amount of prep work you need to do. Do you charge to do a detailed quote? The heat loss calc I need to really learn properly so that I don't screw up on the first hurdle. I've been in the GAS heating industry for 16 yrs now so have a good idea of installations etc... My question is... Does it get easier working all this out?
Yes, you do charge for both quoting and doing the heat loss, hopefully at the same time. You cant do it for free as it is to time-consuming. To do it well it takes time and needs to be paid for. I am still learning and experimenting with how to work things out myself, but it does get easier with every job. My first installs were killing me mentally and physically. Now I can install pretty easily and enjoy the process as well, so it does get easier. It is however a totally different game to what standard gas installs are. Ask your company to put your though heat geek training if you can. Sadly I have not seen any decent training out there apart for HG.
I am about to desing my system and I have a question. If you dont separate the heating from hot water you cant aply any ingredient to protect the underfloor heating pipe. Isnt that an issue ? I always thought that this cemical protection is esential.
Nice and clean install that one ! btw, in the UK we obviously focus on heating but for the few summer months what are the options for cooling, would that just be an air to air system and some other water heating method? Seems to me we need an all in one solution that can do both heating/cooling plus water.
So heat pumps have a life span of 10 years max, no parts available after 10 ? How do you deal with the heat generated in that plant room ? I bet it gets very hot in there, i've just left one and it was no fun at all !! ps, great channel :)
I'm trying to go down the heat pump route, amazing that system only managed 13 years, makes you think how long current units will last, 25 years like people say? Ah well if I could be have an experienced installer to do my system here in Bristol it would settle my mind
well, they are not technically wrong - just not very good and doing things differently improves the system performance by quite a large margin. Doing systems as per standard vaillant schematics ends up with poor performance in most cases.
Awesome video. I thought the Vaillant heat pumps had a pressure relief valve already fitted on the pipework within the outdoor unit so no need for one inside the property. I know Mitsubishi with their R32s dont want an additional pressure relief valve inside due to R32 being flamable, thought R290 would be a bigger no no due to air break on tundish into property. Did the index circuit end up being on the radiators or one of the UFH loops and how would you roughly calculate if you didnt have access to loop lengths?
Vaillant schematics (I know - not to be trusted - lol) show additional PRV on the internal robo kit. The index is deffo UFH. I just had to assume the worst-case scenario - 100mm spacing at the longest possible pipe run of 100m and flow reverse-engineered from calculated heat loss per m2 for the biggest heat loss area.
Love your videos someone who Is a master of there craft, would Love to learn all this, may i ask the costs of a typical heat pump install and running costs compared to gas boilers as I understand they use alot of electricity?
Great work. I've started to see a few ASHPs fitted on brackets bolted to the walls of properties rather than on concrete bases. What do you think of this? Its obviously quicker.
Our home is detached, old and listed - so increasing insulation not really possible. Really good thermal mass, and large windows giving good gain from the sun :) I have made it pretty draft free. I hope to have a heat pump to replace our ageing gas boiler. I would use it to give a good background heat and boost with a woodburner when needed. I currently run our boiler at 30-40 degrees even when it is minus 5 or worse. Would an air source heat pump work for us? Radiators are all plumbed 15mm to each rad, 22 back to boiler, i was thinking to upgrade the last section to 28mm and also 28mm to a new cylinder with the shortest possible runs to the heat pump and cylinder, no zones - add more radiators where required, but honestly, i do not want a super hot house, prefer a low steady heat. I would prefer to do the work myself, but if could find a good installer, that would be fine too :)
@@UrbanPlumbers - Yes, exactly right :) My ideal is for the system to run as 30 - 40 degrees to enable an efficient system, but i do not want the house at 21 plus degrees as many prefer. Is it ok to design the system to have a lower design/internal temperature and so need a smaller heat pump? (as my house is listed, and because of it's specific design, i am restricted as to the changes i can make, so high levels of insulation is not an option). I agree with you - regulations need to work in a practical sense :) Hence i do not necessarily want a design temp i will never actually use (i understand that i can always turn it down and have a more efficient flow and then a higher cop), but also i do not want a larger/or even two heat pumps, if it can be avoided at design stage.
My kitchen looks like that destroyed, a small kitchen and it costs a fortune to run,installed by MCS accredited company 125 floor space 17 KW Grant Aerona2 they are no help take it up with your installer Dynamis Warrington haha a complete rip off,Not everyone knows what they are doing Cowboys rule with no comeback what’s so ever.Your videos are spot on nice one.
@@chriss4949 Thanks. I think this is what i will do. I will do the calculations to achieve a comfortable background temperature around 17 degrees with a flow around 40 degrees, go for an open system (no zones) and weather compensation - in time i will get solar to meet some of the cost of running the pump. They look fairly straight forward to install , so long as i take my time - might be wrong of course :)
Excellent video - very informative as always. Please could you confirm what the black sealant you used was around the external insulated pipework - was this just standard black silicone?
the black sealant is called 'seal and bond' and is specifically developed for external insulation and sold by the same company that supplies the insulation
Thank you for the informative video, do need to change all the pipe work if I am having my oil boiler of 25 yrs plus changed to air source heat pump system 3.5 Kw?
Really nice install mate enjoyed the video! Couple of questions What did you seal the lagging with silicone? And do you have to have a second zone valve on the cylinder for safety shut of like unvented when using a gas boiler? Or is it because the temps do go that high. Cheers Ben
Hi. Thank you for watching. The external lagging is from Primary Pro and you can also get what is called 'bond and seal' sealant specifically designed for this application. It is not silicone and I don't think silicone would work well here. You don't need a second zone valve, as the diverter valve fails safely to a closed position towards the cylinder and is normally open to the heating. It is exactly the same as having 2 x 2 port valves. There is no mid position on that valve. Also, with a heat pump you can't get to more than around 70C in the cylinder.
Great job, just a couple of questions 1. Building regulations for 2 zones on property ove 150m2? I love your ideas of simplicity but would have been so easy to zone it? 2. I had the idea that the blending valve on underfloor protected pipe from excessive temperatures? That there is a maximum floor surface temperature and if HP can do 75Dc could this go to space heating or only DHW pasteurisation?
Space heating is limited in the controller and by the heat curve. You don’t want to be zoning fully weather compensated set ups on heat pumps in most cases. It actually can have a negative effect: lowering efficiency, creating more cycling and making running cost higher. Just see what the compliance following guys get on their installations - it’s usually terrible
@UrbanPlumbers the radiators and underfloor are ok following same curve? Never done heat pumps but did do viessmann training on them 20 years ago. I gave a ecotec plus with vrc700 with VR68 for solar thermal and might be doing kitchen which is last room in bungalow to get floor insulation. The VR62 did have possible external control of bivalent systems, so buy energy supplier.
Excellent video - thanks. Are you aware of any good information on how to calculate if the circulation pump is adequate for the heating system? I would like a direct system and want to know if I need to upgrade pipework..
Well, you need to understand how to calculate your heat loss, then work out the index circuit of the existing system and see what size pump you need by reading the head available on the pump after it goes through the heat source (for that you need data from a heat pump or boiler manufacturer). It requires few skills to do and also usually heat loss software. I use 'heat engineer' for heat loss and a HyTools app to work out pipework pressure loss.
You always start with the heat loss calculations. What are you using to performa heat loss calculation? Can you suggest any easily accessible tool for the advanced and qurious homeowner to do this calculations by himself?
As a heat pump owner and enthusiast this was like a ton of bricks being dropped. Obsolete in 13 years. Thats totally unacceptable in terms.of investment. This is a major elephant in the room. No one will fit one with this short a lifespan and at the cost if they arent supported with spares down the road. Can Vailant be expected to be better? This plays into thr hands of the critics who say theh are too expensive and complicated.
@@colin4685 Actually, using a car constantly is a pretty good idea. I was talking to a taxi driver that had 300K miles on his Skoda Octavia. It still had its original exhaust system on it because it was never stood still long enough for it to rust. It was still on its second clutch because as a professional driver, he was very careful with it.
Parts are absolutely still available for these. They're a meccano set of commonly available; high quality; off the shelf bits. Copeland scroll compressor. SWEP plates. Danfoss TXV. Wilo or Grundfos pumps etc. The instruction manuals for them are a cracking read in certain places. e.g. If XYZ symptoms then your expansion valve might be stuck. Try whacking it as hard as you can with a screwdriver handle a few times. If that doesn't work wind it fully open and shut a few times; then leave it N turns from fully open or closed. Check that superheat and subcooling match these figures and tweak to suit. If it sticks again consider replacing it. All very familiar to anybody who works on old school commercial refrigeration. So a refrigeration engineer would still be able to repair that unit both today and in years to come. Vacuum it down; open it op; clean it up; swap out the broken bits; seal it up and gas it up again. Just like you would with a car that you've just bashed into a deer or similar. I think it's probably fair to say this has been replaced because materially higher performance air source units are now available. These units were really a ground source heat pump intended to work at a fixed speed with ground loops between ~0 and 10C; with the ground having been replaced with a radiator and a fan. On ground source units where the temperatures are stable (ground doesn't change temperature much) and the output power levels are stable (if you reduce flowrate in the ground loop your flow stops being turbulent and performance of the ground loop goes to shit; if you increase flow your pressure drop skrockets and pumping power goes through the roof; so there's a very clear sweetspot that you "always" want to run the ground loop at) it's ok to have a fixed-speed compressor and a mechanical TXV as these do. On air source units the wide operating range (e.g. air at -20C to +30C) and no practical limit on the minimum airflow (it's always turbulent through the fins) really favour inverter drives and electronic expansion valves etc. That's where much of the performance improvements have come from. Agree with the "buy something made in volume" and "in stock with a number of distributors" recommendation. Partly so that a complete unit is available if it goes bang. Partly so that spares are readily available. Also...I'd buy an R290 unit. Propane won't be banned. What will really kill these old R404a units, or indeed R410a / R134a / R32 units, is when you're not allowed to use F-Gases any more.
Love your videos mate, doing a arotherm at this week, got an air brick to the cavity, called vaillant they said it needs to move did they email you proof on the protective zone?
Incredible care and attention to detail on your installs, clearly very proud of your work
Thank you for a nice comment.
Another brilliant video, once my gas boiler dies I'll have to get you to come fit me an ASHP! My neighbour had one fitted by a cowboy and she has had no end of trouble really goes to show that the technology works, the key is a good tradesman. Keep up the good work.
Awesome video, as usual. Interesting to see a retrofit too. Keep up the good work 👌🏼
Thank you for watching !
You're a great example to installers of... anything tbh! You have a focus and an enthusiasm that is inspiring, love your work. I'd like you to reinstall my heat pump, I bet you'd find some over engineering in the system.
I like the professional looking trunking and glands. Unusual for plumbers to reach such electrical professionalism.
Great video, good to hear about the R290 and air bricks in the protected zone. Great install.
Thanks 👍
Another excellent video. We have basically the same system, installed in March of last year. In March this year we had the UFH pump and the upstairs radiator pump removed as they were no longer required. It’s great to see someone else working this out as well. Please keep up the great work.
thank you for watching. The amount of unnecessary pumps and zone valves being installed is mad.
@@UrbanPlumbers if I were to design a house now I would have underfloor downstairs, single Zone. Radiators upstairs with only balancing valves. It’s essentially how our house is running now. We are evening running it with the adaptive heat curve enable. Love it! The new version of the Vaillant app makes a big difference now as well. Keep up the great work.
Great description of how to have a simple install. Getting rid of those pumps will increase the COP a good deal to begin with. And great to see a female plumber. When it comes to mass installs as it will soon having ladies to talk through the system with older folks will make them happier to have one.
Wish I'd known about you earlier!! I had a heat pump installed last year, and the amount of pumps baffles me. (got 3 external pumps, one for upstairs rads, one for downtairs UFH and one for the system, and a LLH) for an average size 3 bed semi. Keeping it simple is almost always the answer.
Never too late to correct it
Great video! we moved into a property which already had an ASHP in place feeding ufh and rads. It also has a buffer tank and extra circulators and we are currently talking with our local installer to have them removed. Already I have disconnected all the actuators to remove room zoning on the ufh. No idea what the scop is as it’s a ten year old heat pump. Your channel has been great to try and understand the essentials of heating system design.
As always just the best info, proper heating system design and insall, no plumbery BS, no designing based on installers own bias. Exemplary on YT.
thank you!
Wow Simon so cool to see your work again, really showing its not that complicated to have a heat pump installed, simplify the system.
I have myself audited many systems, that have been over engineered/pumped, removed those extra pumps them with good results.
See you tomorrow?
You always make it look and sound so easy 😊 Keep it simple as you say 👍
😊 thanks
I applaud you for the highest knowledge. Blows my mind every component to know.
lovely work on the job, was listening to Betatalk episode the other day in regards to the insulation and its nice to see it being put into practice! your episode on there was great too!
Cool, thanks!
As well as being being excellent content. The production quality is excellent 👌.
Thank you
Liked the idea of keeping it simple. Rads at UFH temperature. No zoning.
Excellent presentation. Probably the best on TH-cam for heat pumps. I hope a manufacturer gets you some sponsorship.
Thank you for watching !
Excellent job, wish everyone was like you. thanks for sharing.
I appreciate that!
Nice installation! Affordable and Quality!
It is a joy watching and learning from you.
Excellent work!
Here in Germany, unfortunately, many plumbers are afraid of installing the heat pump without a buffer.
Absolute nonsense =)
The heat pump can only work properly and efficiently if no buffer is installed and it works in the direct circuit.
There is still a lot to learn here in Germany.
Luckily I installed mine myself.
Annual performance factor, measured externally with defrosts... 4.6 😊 (location bavaria)
Check my last video. Mine is running 5.3 now including defrosts and hot water
@@UrbanPlumbers
5.3 is VERY good 👍😉
Here it is -10 to -15°C in winter.... sometimes -20°C, that reduces the work rate quite a bit. Nevertheless, heatpipes are definitely the future of heating 👍
@@energieundhobby Future maybe, but not quite yet for older houses, having a hated cylinder back is a big letdown, and it's too complicated, the plumbing should be one pump internal and one expansion vessel!?!
Hi Simon, now that the gov are increasing the grant to £7.5k I have decided that now is seems to be a good time to go ahead and have an air source heat pump system installed. I am with Octopus and they said that the expected cost to me should be below £3k including any rads, pipework etc (I upgraded my rad three years ago so am hoping my newer ones will be up to scratch. I also had a large unvented cylinder installed which is squeezed into my airing cupboard on the first floor. The boiler was replaced at the same time with a condensing Vailantboiler and it was repositioned to the garage). Octopus will be contacting me to arrange a survey to check out and go over what is needed. I have a small three bed detached house built in 1994 which I had cavity wall insultion pumped in two years ago and I have had a PV (4.8Kw) and battery (14.4kWh) system installed last year, so am hoping my running costs should be a lot lower. The problem I am anticipating is that my house when built was plumbed with microbore (8mm?) and so was wondering if you can comment on this and if it is still viable to have an air source system installed. Also would you be able to carry out my installation, either in conjunction with Octopus, or directly with me? I live in Old Coulsdon, in the southern part of the borough of Croydon. Looking forward to hearing from you. Thanks, Al
Awful technology. Had one for 5 years. It costs a fortune and does not do the job.
@@what-lies-in-your-skiescool story mate.
@mikeypc3592 truth is a hate crime unfortunately in these times.
Very understandable and concise overview of the pipework - thanks!
you are welcome, thanks for watching!
This proves it is better to have a boiler, i would never recoup enough savings over 13 years to justify a heat pump.
No gas
Recently helped a neighbour out with his heat pump hydronic design, because he couldn't find a plumber who knew how to size a heat pump and design the hydronic system. The lack of proper training is abysmal in the UK. You are the one exception, of course😂
yep, 95% are winging it. It is changing though thanks to Heat Geek, Kim's Northampton Heating Academy, and a few others. I spoke to Vaillant, and they will be bringing hydronic courses as well. The movement is slow but in the right direction.
Great to see real world situations/examples .
Very well presented, knowledge is the key here.
Getting to this level should be a basic thing for any heating engineer but like you mentioned need the resources to learn from..
Awesome job! That's how everybody should this little suckers.
awesome as always
Great video!5 Thanks! I’ve learned a lot including how to understand without complicating things.
Your knowledge & workmanship on the hydronic circuit is truly exceptional - but who does the owner call when it goes wrong?
Is it the wet side or the refrigeration circuit that has failed? - my AC biased engineering team would have no issue diagnosing or repairing the refrigeration side of things, but would struggle (or not be interested) in the wet side. Likely to be vice versa for a plumber/mechanical engineer.
Most air to water or ground source heat pumps that come my way have not been correctly designed/installed/commissioned - giving the technology a bad reputation.
Unfortunately, engineers such as yourself are the exception….not the rule.
Please keep up the good work & educational videos.
He's not an Engineer.....he's a plumber
@@hvacdesignsolutions Show me a plumber that can do heat loss calcs & actually commission an UFH system properly (including controls/wiring) & I'll show you my arse! 🤣🤣
These videos are more interesting than they have any right to be. Great advertisement for your skills.
An engineer that can and does calculations in the UK is a rare beast….
On the contrary. Engineer should be a reserved title like lawyer and architect. Proper university educated (or equiv) engineers do calculalations all the time and design complex equipment / systems. Problem is when some installers and 'fitters' start calling themselves engineers. Holland understands the difference and distinguishes between engineers and technicians. This guy clearly knows his stuff; the importance of calculations and simplifying the install.
@@JonPearson-mm1cd the use of engineer is no longer the preserve of the university educated person. In my time as an engineer I have experienced my French colleagues address me as Mr Engineer and London city types look down on me as if I had walked in with dirty coveralls on.
In my mind an engineer is someone that takes the engineering approach and applies appropriate methodology and calculation to the task at hand with the appropriate insight and education whether self taught or formally taught - it is the method and tools that count. I hold two masters and one undergraduate degree however I am not a snob on the topic.
"It uses un insulated blue mains water pipes, which is unusual"
🤣🤣🤣
Great video, communicates the important issues very clearly. Why only one anti freeze valve on the return? I have only previously seen one on the flow and another on the return, an explanation wou;d be greatly appreciated.
Just a note on needing a second pump. 100mm spacing UFH works more efficiently than 150-200mm for low flow temperatures, but it may need to be 'microbore', ie. 8.6mm bore to make the tight bends. Check carefully the pressure loss on the longest loop and you could find an additional pump is required. As long at it's placed after the T off to the UFH, it won't interfere with the modulation of the main circulating pump.
No need for microbire. 100mm spacing can be easily done on 15-16mm pipework. No need for additional circulators
If you use a floating UFH system like Variotherm (ie. not in a screed), that's microbore. It's an excellent system from Austria, no aluminium spreader plates, routed into Fermacell, so more thermal mass than similar XPS ones.
I have seen it mentioned a few time now that you don't put in zone to improve the efficiencies. How much will zoning impact the performance of the system? Is there any way to keep the bedrooms cooler than the living spaces without zoning?
@cillo2000 yes there is - TRVs or actuators to limit the temp without ability to activate the heat source. In practice you can do it just by adjusting flow
I need you to come to France and do my house. You rally are outstanding
Fantastic install. Agree with the simplification, but doesn't this mean the max floor temp will be 40degC? Too hot for some floor coverings. Why no mixing valve on the UFH manifold to reduce the UFH temperature?
That was an excellent explanation of the system swap👏👏
Thank you !
Syzmon that was absolutely excellent.👍 Can I just pick up on your design point of establish head loss of the index circuit and checking the pump curve to ensure it can overcome that. In this situation those calculations enabled you to make two pumps redundant and were able to use the units integral system pump. So, if the integral system pump had been too ‘small’ could you have fitted a larger one without encroaching on manufacturers warranty conditions? Thanks for sharing all this good stuff.😀👍
Not on this heat pump as it’s build on. Separation would be needed
Love your video buddy . Keep it up
👍
With such a large outdoor area, I'm amazed the customer did not go for a Ground Source Heat Pump? It appears the perfect property for it!
ALSO, did you design the system to have radiators and UFH on identical flow temperatures?!?
At 5x the cost and only a slightly higher efficiency?
@@UrbanPlumbers More like 3X the cost (1 metre deep coils), add 1 to SCOP and far more consistent performance even in sub zero temperatures.
Really? You can get ground source for under 30k?
@@UrbanPlumbers After BUS grants of £6K, yes absolutely. As long as you don't have to lay slinkies deeper than 1m.
@@singlendhot8628
Why 1 metre deep?
Incredible work..so neat and tidy. Class.
Great video as ever, says it all about heat pumps that parts are not available after 13 years.
Lovely video as usual! Question about UFH without zone valves or actuators..... did they rely on different spacings to acheive the different temp/ heat loss requirement in different rooms? Seems a high risk strategy to try and acheive that with one constant temp flow through the entire system....... Especially when those controls would be a tiny part of the budget.
Keep up the great work, I love the more technical aspects of your videos!
Yes, it relies on good design and proper commissioning. You can actually adjust flow through different loops and also radiator circuits and match the mean water temperature to the heat loss of the room.
This is not about saving money on installation by not having thermostats or actuators. This is about keeping as much of the system open as possible as it dramatically increases the system efficiency and lowers running costs.
@@UrbanPlumberssince I’d come to ask the same question… is there not a risk then of those various relative flow rates (through the different loops) shifting over time, and then without any active zone control, there would be hot/cold areas in he home? Also, am I right in thinking that there’s only heating in this design when there’s no hot water demand? If so, could this not be problematic? I’m all for the simplification btw - less points of failure, and I understand that maximum efficiency requires maximum flow, but I worry that any imbalance in the system further down the line could be problematic with active controls to keep everything in check.
@@rickwookie imbalance in the system is not really an issue with fully weather-compensated low-temperature systems as it is with high-temperature systems that are prone to overheating.
I have loads of systems running like this with no major issues.
Great work as always keep it up
TOP CONTENT
Awesome video....
I keep being advised to fill the Heat Pump with anti freeze by the manufacturer including Vaillant with the addition cost of a heat exchanger unit so the whole system isn’t filled with anti freeze. I notice this isn’t something you ever do but I’m a little nervous about going against the manufacturers advice.
I'm inclined to use trace heating rather than anti-freeze. The trace heating only comes on where there is any actual risk of freezing, and keeping the external pipework short minimises the cost of installing and then running the trace heating.
Fantastic video as always .
Glad you enjoyed it
Nice little job 😎
Thank you !
Top Job. So what will the customer do to control the manifold surely all the rooms are on constantly?
You are the best
Interesting to learn that the new heat pump can run the DHW to kill legionella but it is close to a COP of 1. Given that the immersion heater is 100% efficient and you will be without heating while the DHW is heating up to 60 deg C I can't see the advantage of getting the heat pump to run the legionella cycle.
You can get to 60c at cop of 2 or over most of the year. It’s only when it’s below 0 that it may drop below 2. Never quite gets to 1.
@@zlmdragon. Rogers is fine. We all seem much worse online.
Top notch mate 👏
Great video as always. Keep it simple stupid is my favorite saying
thank you for watching. KISS definitely works with heat pumps. This is the trouble with the heating industry - everyone tries to overcomplicate things and invent solutions for nonexisting problems that cause real problems instead - if that makes sense.
I'm in the Netherlands and i cannot find anyone as good as you or the heat geeks! Are there any recommendations or do you give an online service for what to buy and to install in my situation?
Great video. I’m going to do the switch. Need a good installer
Look for a Heat Geek Elite installer online. Google 'Heat Geek Map'
It's absolute rubbish that parts are no longer available for a unit only 13 years old. The manufacturer should be ashamed of themselves.
The error code also indicated the fault was with the motor. I've had occasional successes sourcing motors from other suppliers than the original equipment manfacturer. If you can find the motor part number, you might be able to find it somewhere else.
Apparently spares are available for the unit. It may have been a repair man not being aware or else.
@@razvanlex well spotted I did wonder if that could be one of the reasons to replace the unit.
Thanks for pointing this out!
@@razvanlex while you can’t use virgin R404a some systems - you can use reclaimed R404a. Circa 30% dearer but readily available.
Hi Szymon. Fantastic work! Did Vaillant ever email you the confirmation around air bricks? I have a similar situation to overcome.
Yes, vents to subfloor are fine
Thank you
previous Lasted just 13 years how much did it save in running costs ?
Two super expensive heat pumps in 13 years. That’s crazy. What’s the real cost of heating this house?
Super cheap to keep it warm even with the old heat pump as it’s all UFH and a well insulated property. I think they said they used to pay £200 / month last winter. I will update running cost on this job this winter with a follow up video.
Excellent video! Out of interest, is there any reason why you decided not to fit a mag filter?
I don’t think mag filters do anything. I wouldn’t fit them on boilers either. Strainer is all you need.
Great video - thanks. As a designer I wanted to run underfloor and radiators on one pump, but my calculations have shown that I'd need higher temperature for radiators than floor (though both low - eg 40 C radiators, 28 C floor) so have ended up with motorised mixing valve & pump for underfloor, all under heat pump control. I'd rather be on one pump but worry that either the rads will be too cold to do much, or the underfloor will overheat. I do like the absence of manifold actuators and have gone for manual adjusters for user to tweak rooms as required. Will you do an update in winter so we can see how it works in practice?
Yes will deffo do an update in the winter
I can't work out how to size radiators and ufh for the same temperature without fitting very poor ufh.
Why? What makes a ufh ‘very poor’?
@@UrbanPlumbersif I need to run ufh at higher flow temps to match my radiators.
@@andrewmillwardwatford9410 it is not that simple Andrew. It varies from job to job. You can also fine-tune rads / UFH with a gate valve on a return from the rads.
I got 5-6 of those types of jobs installed now, but need to wait for the winter to see how they perform and if they need any additional adjustments.
Tommy Jones is trying an interesting by-pass / CCT concept on heat pumps, where UFH gets a lower temp than rads. He struggles with too much output from UFH on some of his jobs.
My experience is the same - too much output from UFH most of the time and not enough from rads.
Obviously much easier to do the same flow on the same DT - not as you would do on a gas boiler.
My 10 year old 3 bed semi has 10mm plastic pipework feeding all radiators. The main flow and return is under the 1st floor with 10mm pipe work dropping down to the ground floor rads behind the dry lined walls. My question is will all this pipe work have to be replaced.
I work in social housing as an electrician. Where i work now they are still fitting baxi assure boilers, i guess hoping hydrogen will take over from gas (it wont). I think eventually they will be forced to start fitting heat pumps in bulk. But there are many horror stories from social housing tenants of poorly installed and inefficient heat pumps, having been fitted by contractors with no real understanding of them. I really hope there is good training for the people who will end up fitting heat pumps in social housing or tenants will be pushed further into fuel poverty by botched installs.
Air-air and a direct unvented for the social housing stock. Easy on/off controls, people can only heat the rooms they need, and they cost sweet f-all… Air-water needs a different mindset and end user education.
Very interesting video, one thing that keeps me wondering is the Old evaporator had a very long pipe run to the house; advice by British Gas Daikin intaller says maximum 10m run to the hot water tank. can you please comment on allowed length of primary pipework bearing in mind if evaporator cannot be sited close to the house.
Almost any length is possible if it is calculated and sized correctly. You can have way more than 10m but it becomes expensive quickly due to the fact that pipework may have to be of a larger size and will require insulating or boxing or running in pre insulated pipe underground
Look at split units if the evaporator needs to be sized further away
Excellent video again. I'm a home owner building my own home. Struggling to get someone to do overall design so teaching myself. I have UFH upstairs and down at 100 c/c spacing. High insulation and air tightness. High thermal mass. I'm happy that I have built the basics correctly so will only need a small pump to heat a large house at very low flow temps. The bit I'm struggling with is how best to integrate about 7m of solar thermal panels I had built into a south facing roof. Any pointers?
I have a log burner vented back boiler in my workshop that is connected inside the house to a heat exchanger on the return side of an unvented combi boiler heating circuit, it keeps the pressurised system separate and has its own sludge filter. You could do similar with your set up, its like a pre heater before the main heating source.
if your using a new ASHP like the Valiant he's installed you probably would benefit more from selling the thermal panels and installing 400w PV panels/battery storage to power the whole system as long term you will have greater financial and green gains.
What courses do you recommend for getting into air source heat pumps? I'm a gad engineer and trying to move with the times. Don't want to be left behind lol
there is only one course worth doing - one in the description of this video. Ok here you go:
courses.heatgeek.com/ref/20/
The company I'm working for are putting me on a heat pump design and installation PLUS putting me through F Gas.
I love how simple these systems are (Like the old fashion heating systems really) - The thing I'm worried about is the amount of prep work you need to do. Do you charge to do a detailed quote? The heat loss calc I need to really learn properly so that I don't screw up on the first hurdle.
I've been in the GAS heating industry for 16 yrs now so have a good idea of installations etc...
My question is... Does it get easier working all this out?
Yes, you do charge for both quoting and doing the heat loss, hopefully at the same time. You cant do it for free as it is to time-consuming. To do it well it takes time and needs to be paid for.
I am still learning and experimenting with how to work things out myself, but it does get easier with every job. My first installs were killing me mentally and physically. Now I can install pretty easily and enjoy the process as well, so it does get easier. It is however a totally different game to what standard gas installs are.
Ask your company to put your though heat geek training if you can. Sadly I have not seen any decent training out there apart for HG.
which software are you using for heat loss calculations?
Heat Engineer for now
13 years is, honestly, not a long time for a heat source of a house. I want my unit to run for at least twenty years if not longer.
I am about to desing my system and I have a question. If you dont separate the heating from hot water you cant aply any ingredient to protect the underfloor heating pipe. Isnt that an issue ? I always thought that this cemical protection is esential.
Nice and clean install that one !
btw, in the UK we obviously focus on heating but for the few summer months what are the options for cooling, would that just be an air to air system and some other water heating method? Seems to me we need an all in one solution that can do both heating/cooling plus water.
You can cool with this unit. It’s mildly effective
So heat pumps have a life span of 10 years max, no parts available after 10 ?
How do you deal with the heat generated in that plant room ?
I bet it gets very hot in there, i've just left one and it was no fun at all !!
ps, great channel :)
Why no magnetic filter imstalled and dearator?
What was the total cost to replace it and how much kilowatts of electricity does it use per winters day
I'm trying to go down the heat pump route, amazing that system only managed 13 years, makes you think how long current units will last, 25 years like people say? Ah well if I could be have an experienced installer to do my system here in Bristol it would settle my mind
Craig Brooks in Bristol is one of the best installers in the country
@@UrbanPlumbers thanks very much, keep the videos coming! Very informative and interesting 👍🏻
Superb ! this means all Vaillant's schems are wrong.... 😅
well, they are not technically wrong - just not very good and doing things differently improves the system performance by quite a large margin.
Doing systems as per standard vaillant schematics ends up with poor performance in most cases.
All your videos are great
Do you employ any one ?
Does the system you just installed do domestic hot water? Looking for a system that does both and maybe a solar thermal unit on the roof.
Awesome video. I thought the Vaillant heat pumps had a pressure relief valve already fitted on the pipework within the outdoor unit so no need for one inside the property. I know Mitsubishi with their R32s dont want an additional pressure relief valve inside due to R32 being flamable, thought R290 would be a bigger no no due to air break on tundish into property.
Did the index circuit end up being on the radiators or one of the UFH loops and how would you roughly calculate if you didnt have access to loop lengths?
Vaillant schematics (I know - not to be trusted - lol) show additional PRV on the internal robo kit.
The index is deffo UFH. I just had to assume the worst-case scenario - 100mm spacing at the longest possible pipe run of 100m and flow reverse-engineered from calculated heat loss per m2 for the biggest heat loss area.
Great video as always. What are your thoughts on MIXERGY tank with ASHP? via their HP Heat exchanger( House is 5.5kw heat loss 2 persons)
Would be interested in the installation of the heat pump located away from house wall. Down garden how far, how is pipework installed and insulated.?
The best in the business! Do you use software to calculate your pressure loses?
Yes, HyTools App
nice work, i have one question.. do you run the system on antifreeze or just water? thank you.
I never use glycol
Love your videos someone who
Is a master of there craft, would
Love to learn all this, may i ask the costs of a typical heat pump install and running costs compared to gas boilers as I understand they use alot of electricity?
My installs are around 25% cheaper to run than gas. Install cost before the grant £10-15k
when are plumbers going to start labelling all the pipework to its usage?
Why would they? Any half decent plumber knows what is going on and if he doesn’t he shouldn’t be touching it.
@@UrbanPlumbers I would agree, but anything that it non-standard/odd should be labelled to help the next guy/gal out.
Great work. I've started to see a few ASHPs fitted on brackets bolted to the walls of properties rather than on concrete bases. What do you think of this? Its obviously quicker.
It’s actually more difficult and makes servicing difficult - I would only do it as last resort and with single fan units only
Our home is detached, old and listed - so increasing insulation not really possible. Really good thermal mass, and large windows giving good gain from the sun :) I have made it pretty draft free.
I hope to have a heat pump to replace our ageing gas boiler. I would use it to give a good background heat and boost with a woodburner when needed. I currently run our boiler at 30-40 degrees even when it is minus 5 or worse. Would an air source heat pump work for us?
Radiators are all plumbed 15mm to each rad, 22 back to boiler, i was thinking to upgrade the last section to 28mm and also 28mm to a new cylinder with the shortest possible runs to the heat pump and cylinder, no zones - add more radiators where required, but honestly, i do not want a super hot house, prefer a low steady heat. I would prefer to do the work myself, but if could find a good installer, that would be fine too :)
big rads and insulation does not mean a hot house. It means lower flow temperature and much higher efficiency.
@@UrbanPlumbers - Yes, exactly right :) My ideal is for the system to run as 30 - 40 degrees to enable an efficient system, but i do not want the house at 21 plus degrees as many prefer. Is it ok to design the system to have a lower design/internal temperature and so need a smaller heat pump? (as my house is listed, and because of it's specific design, i am restricted as to the changes i can make, so high levels of insulation is not an option).
I agree with you - regulations need to work in a practical sense :) Hence i do not necessarily want a design temp i will never actually use (i understand that i can always turn it down and have a more efficient flow and then a higher cop), but also i do not want a larger/or even two heat pumps, if it can be avoided at design stage.
My kitchen looks like that destroyed, a small kitchen and it costs a fortune to run,installed by MCS accredited company 125 floor space 17 KW Grant Aerona2 they are no help take it up with your installer Dynamis Warrington haha a complete rip off,Not everyone knows what they are doing Cowboys rule with no comeback what’s so ever.Your videos are spot on nice one.
@@Simon-vp3st you can gave whatever you want as long as you dont want the BUS grant👍
@@chriss4949 Thanks. I think this is what i will do. I will do the calculations to achieve a comfortable background temperature around 17 degrees with a flow around 40 degrees, go for an open system (no zones) and weather compensation - in time i will get solar to meet some of the cost of running the pump. They look fairly straight forward to install , so long as i take my time - might be wrong of course :)
Excellent video - very informative as always. Please could you confirm what the black sealant you used was around the external insulated pipework - was this just standard black silicone?
the black sealant is called 'seal and bond' and is specifically developed for external insulation and sold by the same company that supplies the insulation
@@UrbanPlumbers thank you so much
did think you needed actuaters on multy zones for heat loss on different rooms have different heat loss same has balancing rads
No I don’t
Thank you for the informative video, do need to change all the pipe work if I am having my oil boiler of 25 yrs plus changed to air source heat pump system 3.5 Kw?
most likely not. 3.5 is such a small load that it doesn't need large pipework
Love these videos, what fitting are you using to connect the antifreeze valve directly to the heat pump? Thanks
It's just 1''1/4 female to 35mm with a reducer to 28mm and AFV with 28mm compression
Really nice install mate enjoyed the video!
Couple of questions
What did you seal the lagging with silicone?
And do you have to have a second zone valve on the cylinder for safety shut of like unvented when using a gas boiler? Or is it because the temps do go that high.
Cheers
Ben
Hi. Thank you for watching.
The external lagging is from Primary Pro and you can also get what is called 'bond and seal' sealant specifically designed for this application. It is not silicone and I don't think silicone would work well here.
You don't need a second zone valve, as the diverter valve fails safely to a closed position towards the cylinder and is normally open to the heating. It is exactly the same as having 2 x 2 port valves. There is no mid position on that valve.
Also, with a heat pump you can't get to more than around 70C in the cylinder.
Great job, just a couple of questions
1. Building regulations for 2 zones on property ove 150m2? I love your ideas of simplicity but would have been so easy to zone it?
2. I had the idea that the blending valve on underfloor protected pipe from excessive temperatures? That there is a maximum floor surface temperature and if HP can do 75Dc could this go to space heating or only DHW pasteurisation?
Space heating is limited in the controller and by the heat curve. You don’t want to be zoning fully weather compensated set ups on heat pumps in most cases. It actually can have a negative effect: lowering efficiency, creating more cycling and making running cost higher.
Just see what the compliance following guys get on their installations - it’s usually terrible
@UrbanPlumbers the radiators and underfloor are ok following same curve? Never done heat pumps but did do viessmann training on them 20 years ago.
I gave a ecotec plus with vrc700 with VR68 for solar thermal and might be doing kitchen which is last room in bungalow to get floor insulation. The VR62 did have possible external control of bivalent systems, so buy energy supplier.
Excellent video - thanks. Are you aware of any good information on how to calculate if the circulation pump is adequate for the heating system? I would like a direct system and want to know if I need to upgrade pipework..
Well, you need to understand how to calculate your heat loss, then work out the index circuit of the existing system and see what size pump you need by reading the head available on the pump after it goes through the heat source (for that you need data from a heat pump or boiler manufacturer). It requires few skills to do and also usually heat loss software. I use 'heat engineer' for heat loss and a HyTools app to work out pipework pressure loss.
You always start with the heat loss calculations. What are you using to performa heat loss calculation? Can you suggest any easily accessible tool for the advanced and qurious homeowner to do this calculations by himself?
yes, just use 'heat punk'
As a heat pump owner and enthusiast this was like a ton of bricks being dropped. Obsolete in 13 years. Thats totally unacceptable in terms.of investment. This is a major elephant in the room. No one will fit one with this short a lifespan and at the cost if they arent supported with spares down the road. Can Vailant be expected to be better? This plays into thr hands of the critics who say theh are too expensive and complicated.
I replace 13 year old boilers all the time. No difference. You want to drive about in a 13 year old car that's been running 24/7? Didn't think so
Well installed modern units should last 20 years
@@colin4685 Actually, using a car constantly is a pretty good idea. I was talking to a taxi driver that had 300K miles on his Skoda Octavia. It still had its original exhaust system on it because it was never stood still long enough for it to rust. It was still on its second clutch because as a professional driver, he was very careful with it.
Parts are absolutely still available for these. They're a meccano set of commonly available; high quality; off the shelf bits. Copeland scroll compressor. SWEP plates. Danfoss TXV. Wilo or Grundfos pumps etc.
The instruction manuals for them are a cracking read in certain places.
e.g. If XYZ symptoms then your expansion valve might be stuck. Try whacking it as hard as you can with a screwdriver handle a few times. If that doesn't work wind it fully open and shut a few times; then leave it N turns from fully open or closed. Check that superheat and subcooling match these figures and tweak to suit. If it sticks again consider replacing it.
All very familiar to anybody who works on old school commercial refrigeration.
So a refrigeration engineer would still be able to repair that unit both today and in years to come. Vacuum it down; open it op; clean it up; swap out the broken bits; seal it up and gas it up again. Just like you would with a car that you've just bashed into a deer or similar.
I think it's probably fair to say this has been replaced because materially higher performance air source units are now available.
These units were really a ground source heat pump intended to work at a fixed speed with ground loops between ~0 and 10C; with the ground having been replaced with a radiator and a fan.
On ground source units where the temperatures are stable (ground doesn't change temperature much) and the output power levels are stable (if you reduce flowrate in the ground loop your flow stops being turbulent and performance of the ground loop goes to shit; if you increase flow your pressure drop skrockets and pumping power goes through the roof; so there's a very clear sweetspot that you "always" want to run the ground loop at) it's ok to have a fixed-speed compressor and a mechanical TXV as these do.
On air source units the wide operating range (e.g. air at -20C to +30C) and no practical limit on the minimum airflow (it's always turbulent through the fins) really favour inverter drives and electronic expansion valves etc. That's where much of the performance improvements have come from.
Agree with the "buy something made in volume" and "in stock with a number of distributors" recommendation. Partly so that a complete unit is available if it goes bang. Partly so that spares are readily available.
Also...I'd buy an R290 unit. Propane won't be banned. What will really kill these old R404a units, or indeed R410a / R134a / R32 units, is when you're not allowed to use F-Gases any more.
@@colin4685 But boilers are cheap to replace.
Love your videos mate, doing a arotherm at this week, got an air brick to the cavity, called vaillant they said it needs to move did they email you proof on the protective zone?
Yes, it is in the quick installation manual pdf, peg 8 or 9. Some vaillant guys haven’t got the update it seems