At last!!! Thanks be to God and you. I can't believe I found exactly what I needed after more than one week being searching every day. Just as a no native English speaker very hard to catch up your fast speaking. Thank you
This helped me understand what was going on in the wiring centre, disconnect my old stat (at both ends) and add in a hive receiver next to the centre - great video, thanks
John ward - Aka - JW - is by far the most concise teacher and greatest electrician on the net. Anytime im stuck - JW - pulls me from the muddy waters. Thanks JW 1UP
I love your vids. Trying to be a sparky for many years even tho passed out NVQ 1-2-3 2010. Could not get proof of work done as lack of interest from sparks if your over 19 slave labour rate. Sorry for rant. Anyway your vids are so good and helpful for some one who has little time on the tools but still interested in staying relevent. You really are a valuable source thank you.
Am a plumber but just couldn’t find a good diagram for adding underfloor heating to Combi with two zone valves and modern 230v programmable thermostats.... thank you, after five mins watching, my brain clicked into gear... the wiring diagrams I had still don’t make sense but it’s all working now thanks to you...
Hi Andy, I am looking for the same thing connecting underfloor heating to combi but not sure how to do it. I would very appreciate it if you could let me know how you did it. Many thanks
Excellent explanation, I have never worked with a boiler or any electrical wiring other than dashcams and the odd splice into a car live wire for some 12v power. After watching your video, I was able to setup zone 1 of my Hive Dual Zone heating to replace my current thermostats, took me around 40mins including stripping/trimming cables, now I just need to cable tidy and then do the second one! Really appreciate this video and diagrams, very informative and right to the point. Hive wanted £175 for this install, all I need is a little trunking but the rest is neat so i'm happy! :) - Anyone reading this comment thinking of having a go, just make sure you invest in an electrical tester to make sure the switch is isolating the circuit correctly as explained in this video, better safe than barbecued!
Very clear explanation / description. No programmer is shown in this. Not often mentioned in various explanations available (which often show a HW. cyl stat); is that most /all combi systems have no HW cylinder or stat & the boiler supplies HW on demand. I assume a combi's HW output is triggered by an internal flow valve; you turn tap, water flows, flow switch operates, boiler fires. All that is needed are the zone stats to fire the CH as shown in your video plus a timer/programmer to automate CH. The HW side of the programmer is unnecessary in this set up.
Had to wire a combi to a cylinder as well as central heating through 2 x2 ports 10 years ago, what a head scratcher that was, had to run it through a relay switch if I remember correctly.
Should basically just be the same only with three zones instead of 2. Unless you want hot water priority, (ie if hot water is demanded then heating is off). In that case you’d do something fancy with the NO and NC contacts of the hot water thermostat contact. Specifically, the power that goes to the heating side of the system should be on the NC side of the hot water thermostat, so the whole heating side turns off when the water is demanded.
Very clear and professional video. I have a couple of questions pls. 1) which brand wiring centre would you recommend for Hive, and 2) I am trying to understand how the bypass will be installed (or what it looks like pls in a setup). Thank you ever so much
Great video, very clear. The issue I have at a client's property is that the wiring centre is at the opposite end of the house from the boiler and where the new Hive reciever would be. Currently there is only a 3 core and earth from the boiler/reciever area to the wiring centre which leaves me 1 core short. Would it be possible to supply the L,N and E to the pumps locally at the wiring centre ( fused down ) and use 2 of the cores in the existing 3 core and earth plus the earth as the switch cores? this would mean that there would be 2 circuits at the wiring centre. I would clearly label this at both ends but Im just wondering if it is ok or a total no no? Thanks in advance.
Hi JW, On pin 9 when both stats call for heat, why doesn't the voltage from both valves either add to create 440v assuming they are in phase or cancel to 0v if there's a 180deg phase shift introduced, with the first point being most likely.
Just find this video very good explanation. I wish someone make video about 2 zone heating with 2 pump or more with Relay to stop backfeed one for other. Always confuse me that systems 😂
Could you connect the grey and brown wires together at the 2 port valves, and then ditch the perm live to the valve? You would still have the ability to switch on the boiler with the postition switch within the valve, however it would be fed from the programmer not the main live. You would then only need 3Core + Earth cable
Having an issue with our central heating system. I have a brand new thermostat, and dual zone heating. The heat pumps both work as I can wire them each to the upstairs thermostat which works but I cannot get the downstairs thermostat to call for heat even though it ‘clicks’ when turned up. Any ideas what this could be?
If I wanted to move a radiator from one heat zone to the other and the radiators share a wall with pipes inside. Can I just daisy chain or will I need the floors up...
Will this work with valiant ecotec plus 832 Combi boiler? It has connections ‘RT’ next to ‘LNPE’ inside this boiler. The RT connection has 2 terminals though? This is a 2 zone system with the Drayton 230v ZA5 2-port valve. I am also installing 2 thermostats, they are the danfoss TP5001M 230v with V/F output. I am right in saying the switch line to the thermostat will connect to normally open contact? Great video by the way, any advice would be appreciated!
Will the central heating thermostat be able to switch an external heating pump on directly aswell as the boiler. I have a combi boiler and I think the internal heating pump is not powerful enough to pump water around the house. I want to put an external pump in the system but need it to be controlled so it turns on and off and not powered all the time. Looking at the circuit diagram on your video, instead of having zone valves can the thermostat control the external pump the same I.e when thermostat is turned to required temperature the pump starts. Thanks
Currently considering switching to tado smart heating. Have ESI wiring centre plug and play in at the moment (new build). Need to swap to a more analog wiring centre. 2 zones. Combi. Will this work?
Thank you John. I'm not an electrician but have benefitted from so many of your videos. I have a problem relating to the above. We have fitted a Heatmiser UH4 control unit with wired 230v Neostat V2 thermostat/timers. The Heatmiser gives the option to run underfloor heating zones along with a radiator circuit. I wondered if you have any knowledge of those products? The electrician is scratching his head because our Worcester Bosch Greenstar boiler asks for a 230v supply to its switching, the Heatmiser wiring diagram seems to show a volt free connection coming from the control unit. As a result, the boiler doesn't switch off at any time. Sorry if all of that is confusing.
Thanks for explaining this so clearly John. I'm fitting 2 Hive single-channel thermostats and I thought I was going to have to wire the receivers into the circuit through a new spur or something.. I'm pleased to see it's easier than that! I have a few questions (excuse my ignorance!) 1. On your diagram of the wiring to thermostat / receiver it shows the same connection from L on the boiler going to L and 1 on the receiver. The Hive wiring diagram labels L as Permanent Live and 1 as Common. I just want to check that I need to use a short piece of wire to bridge between L and 1 on the receiver? 2. What specification ofcable should I use for this? 3. I see some of the connections on the wiring centre have as many as 3 wires going into them. Do they all fit in the hole or will I need a connection block to connect the 3 wires into the hole?
just what i am about to do, one for the kitchen and bathroom and one for the rest, only need the kitcen and bathroom most of the time as wood burner does the rest.
It'd be better with ONE 3-port valve instead of 2 two-port valves. Won't need an automatic bypass for pump overrun and means only need to wire one valve in.
4:34 You won't need an automatic bypass valve if you use one 3-port valve instead of 2 two-port valves. I think the wiring would be a lot simpler too - leave the existing set-up and just add the 3-port valve and new thermostat.
There would potentially be complications with the wiring You would need a wire from one of the heating zones for when heat is NOT required for that zone, due to how 3 port valves work For example, wire A from the valve would be heat required for zone 2, and wire B would be heat NOT required in zone 1 (as both wires A and B have to be powered for the valve to move all the way across to zone 2 only, and removing power from both wires will cause the valve to return to zone 1 only, if you were to only power wire A, the valve will stop at the half way position)
Hi John, just what I was after, Great, Thank you. Same principle as your diagram etc but one circuit will be radiators, the other will be for UFH in a single zone. I'm just a bit confused as to where the return pipe would fit into this as 2 separate circuits? Would I need a third 2 port valve for the UFH return and just two 2 port valves on the flow side, one for UFH and one for Rads as per your diagram? Kind regards, Paul
@@jwflameTHANKYOU! I did consider that but won't UFH return interfere/mix with Rad return as that's on different circuits with diff pressures? So in a nutshell, the same as your diagram? Cheers, Paul
Hi John. Great video. Any advice for the best smart heating system which I could retrospectively add to my boiler (opentherm compatable) and underfloor heating (7 zones). As I have basic stats today it's working as a simple 'On(100%)/Off' system which means i often overshoot my desired temp and my floor is often too hot. I think I need to find stats which enable modulation (individually for all zones) but I'm struggling to find the right manufacturer. Thanks!
Nice vid thanks ..might be worth mentioning that if using a Honeywell wiring centre and going on their wiring diagrams the bridging in center may cause confusion for future fault finding if engineers are following Honeywell guides. Not a criticism just an observation. Great , clear info . Would like your thoughts on the best way you would use to balance the returns if say downstairs is bigger than upstairs . Thanks for taking for a great presentation.
UFH pump is connected to the thermostat for that zone, so it only runs when that zone requires heat. Thermostat 3 in the diagram, which is also the brown wire for the valve.
It doesn't. No one should be installing new Y plan / 3 port valves, they are only suitable for a system with hot water and a single heating zone, nothing else. To add more zones or a hot hot water cylinder, it's another thermostat and a 2 port valve. Other videos covering those: th-cam.com/play/PLVsHvs2Suqmr5HtxgbInR4bXmH0kLseWc.html
Hi John I have a Greenstar combi CDI with comfort 11 RF installed, following your diagram to the letter. everything plumbed and wired. Looking at the boiler wiring I find that LS is linked to LR so I am now stuck as when to put the orange wires from the 2 port valves.
The link is removed, the orange wires connect to LR. The link is there so that the boiler will run all the time when heating is selected on the front panel, it's intended for testing purposes only when the boiler is installed.
Diagrams and instructions are very precious and clear I wonder if there are any possibilities of wiring zone valve and 3 port motorised valve in a single wiring centre. While I was on unvented course the instructor told me we could wire two different valves but I like to know how. It will be very grateful if you could made such video please? Thank you JW
It'd be better with ONE 3-port valve instead of 2 two-port valves. Quite possibly in upstairs downstairs case, heating on both likely not necessary. If they are both needing heat, another switch is required to allow the 3-port valve to return to its mid position.
On a 2 zone combi system. Could both valves be removed and pipe work bridged where the valves are removed and a simply receiver and stat be added directly to the boiler for call for heat without altering any other pipework?
Brillant video , thanks . I am in a process of connecting an UFH ( zone 1) and radiator system (zone 2) I am using 2 2port valves as the UFH is only 1 large room , 2 hive thermostats , I am struggling to understand where to wire the UFH pump . any videos of yours available on that subject ?
For a single UFH zone, the pump is wired to the thermostat switched output, so it runs at the same time that the valve is open. Terminal 7 or 8 in the diagrams in the video.
As far as I know, opentherm would not be possible with a multi-zone system, as opentherm takes over control of the boiler (opentherm is a digital connection that goes straight to the boiler from the thermostat)
JW, cheers your videos are fantastic. I have a question if I may. My boiler doesn't appear to have a switched live. I currently has a link in place labeled ROOM STAT/TIMER. My boiler is constantly firing up even though the thermostats are off. Have you seen this before?
That link is supplied with the boiler, so it can be powered up immediately after installation without having to connect external timers or thermostats, mainly so that the gas side of things can be set up properly. Normally that link is removed, and it's those same terminals where the room thermostat or other controls are connected. However some boilers have multiple options for connecting external thermostats, so you will need to check the installation instructions for your particular boiler.
How would I remove the second zone? We have a very small second zone in our bedroom and ensuite that we do not use as the thermostat makes a big CLUNK when it turens on or off and wakes me up! I'd rather have the entire house come on and off together.
Find the brown wire for the zone valve in the wiring centre and connect it to the brown wire for the other zone valve. They will then both work together from the same thermostat.
Not without extra components and thermostats which had both on and off connections. 3 port valves were designed decades ago for one type of installation - a hot water cylinder and a single heating zone. They are of little or no use for anything else.
Hi sorry to be i bit cheeky John I'm stumped I have been searching for a wiring dia. for a system with Keston c40 with two switched live, one for heating and other hot w. I had an oversized cylinder made up with a solar coil and heating coil high and low immersion bosses and used it in an extension I built so have two cylinders now, I have two heating zones two-pipe and underfloor with Danfos radio linked stats with their own timers built-in, I want all four zones independent and I am ok with two programmers, any idea where to look for guidance, been in the heating industry for 30 years but pulled a blank on this one. I'm retired on ill-health for some years so out of touch with colleagues to draw from, any help will be appreciated Cheers Mike R.
Hi , I have this system , I have 2 ESI programmable room stats . I would like to put open therm connected to my system , any idea what would be involved to do this , thanks
Opentherm with multiple thermostats is not possible to do unless they are wireless ones that share a single receiver (as opentherm uses digital communication between the thermostat and boiler, and it isn’t designed to allow multiple thermostats, with wireless thermostats, only 1 wireless receiver can be connected to the boiler using opentherm, and you cannot wire a second thermostat/reciever up without getting strange behaviour, such as the boiler only running when BOTH thermostats are calling for heat, or the boiler only responding to one thermostat, or perhaps even the boiler showing error codes and/or not responding to either thermostat)
hi John. thanks a lot, helpful stuff. The plumber has attached an extra Wilo Para pump to the zone 1 side (to help with underfloor heating). Would I attach the live (of the pump) to number 9 in the wiring centre? (the pump only has L,N and E) That way, it would come on when called for by thermostat receiver 1? or is the incorrect? anyway else could help too? thanks
No, if connected to 9, that pump will run when the boiler is on regardless of which thermostat is used. If it's for zone 1 only, connect it to 7, which is the switched output of that thermostat only. Numbers refer to the diagram in the video, your installation may have a different arrangement. The UFH pump should be part of a manifold with a mixing valve, so it only pumps water for the UFH, and nothing else.
Thank you Mr John for clarifing and simplifying. I have a question. Do we need a programmer? Just thermostat enough? And what about hot water how it is controlled for each zone? Many thanks
The arrangement in this video would be used with modern programmable thermostats, which have both time and temperature settings. it would be possible to use a separate programmer/timer and thermostat but there is no point - it would cost more, be more complex to install and provide worse control of the heating. There is no control of hot water here - combination boilers heat the hot water on demand. Other videos in this series cover hot water controls, th-cam.com/play/PLVsHvs2Suqmr5HtxgbInR4bXmH0kLseWc.html
This is a great overview. One thing that's always confused me (as a lay person), is the circuit route (thermostat -> wiring board -> boiler) carrying the actual power for the boiler itself? Or just enough power to 'activate' the boiler, which then draws running power from an independent connection?
The thermostat is just an on/off signal to the boiler. Also note that this wiring is intended for gas or oil boilers, so the electrical power used is only for the pump and controls, typically under 100 watts. Electric boilers do exist, they would have a separate high power connection for the heating elements, with the thermostat wired as here, just for on/off control.
E&N to the earth and neutral terminals. L to the switched output of the thermostat (3 in the diagrams, also the same as the brown valve wire), so the pump only runs when heat is required for that zone.
Hi Quick Question , If Zone 2 was a UFH system ( pump & Actuators ) would i attach their 230v Power To point 8 ? on the diagram . So they would switch off when the Hive is turned off ? . Would this also work if Zone 1 and 2 was on at the same time and i turned off the UFH/Zone2 ( would the Pump and UFH turn off ) ( I assume they wouldnt be getting any power from the orange ? )
@@robday3968 Rob , I converted my single zone to dual zone ( UFH and Radiators ) last weekend . From my UFH wiring i had a Brown & Grey wire ( Brown Sleeve ) . These both connected to point 8 on the diagram . This then meant the pump and actuators turned off with the zone . My setup was using two Hive thermostats .
I've a buffer thermal storage tank. I need to turn on a load when top stat drops to 45c and not turn off until bottom stat reaches 50c. Can anyone tell me what device I need to do this? tia
Is it possible to have a 24v thermostat connected to the zone valve controlling the radiators and a 230v stat connected to the zone valve controlling the u/floor heating on the same combi boiler? It’s a valliant combi. I’m pretty sure I can but just wanted some reassurance 😁
If the 24V thermostat just uses 24V for power and has volt free contacts, then it could be used, the thermostat contacts would switch the 230V for the zone valve as in the video. If the thermostat switched output is also 24V, then it would would require a relay with a 24V coil, the 24V thermostat would power the relay coil and the relay contacts would switch the 230V power to open the valve. In both cases the thermostat would require a 24V supply from somewhere.
That’s a great video thank you. Would it be the same for underfloor heating zone valve instead of two central heating zone valves? If so how would I connect the pump wiring? Many thanks
The valve is the same. If it's just a single zone, the pump is wired to the switched output of the thermostat, the same terminal as the brown wire to the valve. For systems with multiple UFH zones, a separate UFH controller would be used, which will have connections for the pump, actuators and thermostats.
UFH has it's own pump, which for a small single zone would be connected to the thermostat for the UFH. For larger installations with multiple zones, the UFH pump is connected to a dedicated controller/wiring centre for the UFH together with the thermostats and zone actuators.
Hi, I have this type of set up on my system. But I cannot control zone two independently. Boiler receives the signal, the burner starts and goes off quickly. Valve 2 is opened but I have no flow inside radiators. CH flow is hot but CH return is cold. But when zone 1 calls for heating both zones are heating. Any clues?
If this is a new problem then most likely is a blockage or air lock on zone 2 somewhere. If it's always been like that then incorrect pipework is also possible.
![สาวเมืองเพชร - ธีเดช ทองอภิชาติ [Official MV]](http://i.ytimg.com/vi/kEt7F9PvO3I/mqdefault.jpg)
Probably the best explanation of wiring zones valves I have heard
I was really impressed too. The marker drawing/diagram was basic but very effective
A fantastic yet simple explanation of multiple heating zones.
Many thanks John from all learning this.
Thank you for a most thorough but concise and informative explanation JW.
I'm a sparks and I know this stuff inside out and I'm still watching these vids says a lot for the channel.
JW - is by far the most concise teacher. ( Thank You John W. For this Great Video )
At last!!! Thanks be to God and you. I can't believe I found exactly what I needed after more than one week being searching every day. Just as a no native English speaker very hard to catch up your fast speaking. Thank you
The best video going when it comes to understanding the wiring of a 2-port valve. Who would have thought brown doesn't go to brown!?!! Thank you :)
Clear, concise and straight forward explanation. Best one on YT. 👍🏼
This helped me understand what was going on in the wiring centre, disconnect my old stat (at both ends) and add in a hive receiver next to the centre - great video, thanks
Amazing. I’m a sparky and still benefited greatly from your explanations and delivery. Thanks.
Brilliant tuition and video John, very well presented and animated, best on the internet, helped me instantly, thank you!
John ward - Aka - JW - is by far the most concise teacher and greatest electrician on the net.
Anytime im stuck - JW - pulls me from the muddy waters.
Thanks JW 1UP
I love your vids. Trying to be a sparky for many years even tho passed out NVQ 1-2-3 2010. Could not get proof of work done as lack of interest from sparks if your over 19 slave labour rate.
Sorry for rant. Anyway your vids are so good and helpful for some one who has little time on the tools but still interested in staying relevent.
You really are a valuable source thank you.
most easiest to understand explanation of wiring controls ever
Absolutely fantastic. Easily the best diagram and explanation . 👍🏻
Am a plumber but just couldn’t find a good diagram for adding underfloor heating to Combi with two zone valves and modern 230v programmable thermostats.... thank you, after five mins watching, my brain clicked into gear... the wiring diagrams I had still don’t make sense but it’s all working now thanks to you...
Hi Andy,
I am looking for the same thing connecting underfloor heating to combi but not sure how to do it. I would very appreciate it if you could let me know how you did it. Many thanks
Thank you John
For explaining how to zone on 230 volts.
John, you're explanations are superb. Really first class stuff. The paxman like delivery is a bonus too :-) . Thanks.
Thanks for this video, it completely helped me wire 2 zones to a combi!
Excellent explanation, I have never worked with a boiler or any electrical wiring other than dashcams and the odd splice into a car live wire for some 12v power.
After watching your video, I was able to setup zone 1 of my Hive Dual Zone heating to replace my current thermostats, took me around 40mins including stripping/trimming cables, now I just need to cable tidy and then do the second one!
Really appreciate this video and diagrams, very informative and right to the point.
Hive wanted £175 for this install, all I need is a little trunking but the rest is neat so i'm happy! :) - Anyone reading this comment thinking of having a go, just make sure you invest in an electrical tester to make sure the switch is isolating the circuit correctly as explained in this video, better safe than barbecued!
This could be sold as a training video!!! Thanks JW!
Excellent information
Amazing. Great clear and thorough video. Thank you
Brilliant very professional and well set out. Best one on TH-cam keep it up 👍👍
Excellent video. Just what I needed.
Very clear explanation / description. No programmer is shown in this. Not often mentioned in various explanations available (which often show a HW. cyl stat); is that most /all combi systems have no HW cylinder or stat & the boiler supplies HW on demand. I assume a combi's HW output is triggered by an internal flow valve; you turn tap, water flows, flow switch operates, boiler fires. All that is needed are the zone stats to fire the CH as shown in your video plus a timer/programmer to automate CH. The HW side of the programmer is unnecessary in this set up.
Excellent as always! Thank-you.
You are a great teacher 🎉🎉🎉
Just what I was after - great vid
Well explained. Thank you John, you're could be a good training teacher!
John, you are the best 👏🏼👏🏼👏🏼👍🏼
Excellent explanation. Thank you.
Brilliant explanation 👏
Fantastic explanation JW thank you so much.
I really enjoy your work, BR
Had to wire a combi to a cylinder as well as central heating through 2 x2 ports 10 years ago, what a head scratcher that was, had to run it through a relay switch if I remember correctly.
Should basically just be the same only with three zones instead of 2. Unless you want hot water priority, (ie if hot water is demanded then heating is off). In that case you’d do something fancy with the NO and NC contacts of the hot water thermostat contact. Specifically, the power that goes to the heating side of the system should be on the NC side of the hot water thermostat, so the whole heating side turns off when the water is demanded.
Thank you very much, you’re the best !!! Very good explanation and made a lot of sense.
Very clear and professional video. I have a couple of questions pls. 1) which brand wiring centre would you recommend for Hive, and 2) I am trying to understand how the bypass will be installed (or what it looks like pls in a setup). Thank you ever so much
Brilliant John.
Great video. Thanks
Great video, very clear. The issue I have at a client's property is that the wiring centre is at the opposite end of the house from the boiler and where the new Hive reciever would be. Currently there is only a 3 core and earth from the boiler/reciever area to the wiring centre which leaves me 1 core short. Would it be possible to supply the L,N and E to the pumps locally at the wiring centre ( fused down ) and use 2 of the cores in the existing 3 core and earth plus the earth as the switch cores? this would mean that there would be 2 circuits at the wiring centre. I would clearly label this at both ends but Im just wondering if it is ok or a total no no? Thanks in advance.
Hi JW, On pin 9 when both stats call for heat, why doesn't the voltage from both valves either add to create 440v assuming they are in phase or cancel to 0v if there's a 180deg phase shift introduced, with the first point being most likely.
Thx so much…i was searching for this…
Just find this video very good explanation. I wish someone make video about 2 zone heating with 2 pump or more with Relay to stop backfeed one for other. Always confuse me that systems 😂
Great video. I'm wiring ideal vogue what changes would I need to make for the set up to work?
Understood up to the part of connecting first three wires brown blue earth. After that is become complicated. Also which wires to use 1.5mm2 ???
Could you connect the grey and brown wires together at the 2 port valves, and then ditch the perm live to the valve? You would still have the ability to switch on the boiler with the postition switch within the valve, however it would be fed from the programmer not the main live. You would then only need 3Core + Earth cable
Excellent video, well explained!
Mate you a legend
This is really good. Thank you.
Thank you for lovely explanation really helpful video
Thanks Dude. Love your vids.
Hello. How can we connect boiler to wiring centre if it is on a distance in the middle of the house with manifold.? Do we need a long wire.?
Having an issue with our central heating system. I have a brand new thermostat, and dual zone heating. The heat pumps both work as I can wire them each to the upstairs thermostat which works but I cannot get the downstairs thermostat to call for heat even though it ‘clicks’ when turned up.
Any ideas what this could be?
If I wanted to move a radiator from one heat zone to the other and the radiators share a wall with pipes inside. Can I just daisy chain or will I need the floors up...
Will this work with valiant ecotec plus 832 Combi boiler? It has connections ‘RT’ next to ‘LNPE’ inside this boiler. The RT connection has 2 terminals though? This is a 2 zone system with the Drayton 230v ZA5 2-port valve. I am also installing 2 thermostats, they are the danfoss TP5001M 230v with V/F output. I am right in saying the switch line to the thermostat will connect to normally open contact? Great video by the way, any advice would be appreciated!
Will the central heating thermostat be able to switch an external heating pump on directly aswell as the boiler. I have a combi boiler and I think the internal heating pump is not powerful enough to pump water around the house. I want to put an external pump in the system but need it to be controlled so it turns on and off and not powered all the time. Looking at the circuit diagram on your video, instead of having zone valves can the thermostat control the external pump the same I.e when thermostat is turned to required temperature the pump starts.
Thanks
Spot on explanation really helpful
Dose the same principle apply if your second zone is underfloor heating?
Currently considering switching to tado smart heating. Have ESI wiring centre plug and play in at the moment (new build). Need to swap to a more analog wiring centre. 2 zones. Combi. Will this work?
brilliant explanation. thank you.
Another excellent video...
Thankyou very much very well explained
It'd be better with ONE 3-port valve instead of 2 two-port valves.
Based on this can you add Unvented cylinder instead ?
Thank you John. I'm not an electrician but have benefitted from so many of your videos. I have a problem relating to the above. We have fitted a Heatmiser UH4 control unit with wired 230v Neostat V2 thermostat/timers. The Heatmiser gives the option to run underfloor heating zones along with a radiator circuit. I wondered if you have any knowledge of those products? The electrician is scratching his head because our Worcester Bosch Greenstar boiler asks for a 230v supply to its switching, the Heatmiser wiring diagram seems to show a volt free connection coming from the control unit. As a result, the boiler doesn't switch off at any time. Sorry if all of that is confusing.
Great vlog as usual but where is your time control as required by current regulations
Thanks for explaining this so clearly John. I'm fitting 2 Hive single-channel thermostats and I thought I was going to have to wire the receivers into the circuit through a new spur or something.. I'm pleased to see it's easier than that! I have a few questions (excuse my ignorance!)
1. On your diagram of the wiring to thermostat / receiver it shows the same connection from L on the boiler going to L and 1 on the receiver. The Hive wiring diagram labels L as Permanent Live and 1 as Common. I just want to check that I need to use a short piece of wire to bridge between L and 1 on the receiver?
2. What specification ofcable should I use for this?
3. I see some of the connections on the wiring centre have as many as 3 wires going into them. Do they all fit in the hole or will I need a connection block to connect the 3 wires into the hole?
Excellent explanation.
just what i am about to do, one for the kitchen and bathroom and one for the rest, only need the kitcen and bathroom most of the time as wood burner does the rest.
It'd be better with ONE 3-port valve instead of 2 two-port valves. Won't need an automatic bypass for pump overrun and means only need to wire one valve in.
4:34 You won't need an automatic bypass valve if you use one 3-port valve instead of 2 two-port valves. I think the wiring would be a lot simpler too - leave the existing set-up and just add the 3-port valve and new thermostat.
Can u plz explain further….. i need to understand
@@Aliens4world A 3-port valve cannot be completely closed. There is always possible flow one way, or the other or both.
@@millomweb thx
There would potentially be complications with the wiring
You would need a wire from one of the heating zones for when heat is NOT required for that zone, due to how 3 port valves work
For example, wire A from the valve would be heat required for zone 2, and wire B would be heat NOT required in zone 1 (as both wires A and B have to be powered for the valve to move all the way across to zone 2 only, and removing power from both wires will cause the valve to return to zone 1 only, if you were to only power wire A, the valve will stop at the half way position)
Hi John, just what I was after, Great, Thank you. Same principle as your diagram etc but one circuit will be radiators, the other will be for UFH in a single zone. I'm just a bit confused as to where the return pipe would fit into this as 2 separate circuits? Would I need a third 2 port valve for the UFH return and just two 2 port valves on the flow side, one for UFH and one for Rads as per your diagram? Kind regards, Paul
The return pipes just join together, no valves required.
@@jwflameTHANKYOU! I did consider that but won't UFH return interfere/mix with Rad return as that's on different circuits with diff pressures? So in a nutshell, the same as your diagram? Cheers, Paul
Hi John. Great video. Any advice for the best smart heating system which I could retrospectively add to my boiler (opentherm compatable) and underfloor heating (7 zones). As I have basic stats today it's working as a simple 'On(100%)/Off' system which means i often overshoot my desired temp and my floor is often too hot. I think I need to find stats which enable modulation (individually for all zones) but I'm struggling to find the right manufacturer. Thanks!
Nice vid thanks ..might be worth mentioning that if using a Honeywell wiring centre and going on their wiring diagrams the bridging in center may cause confusion for future fault finding if engineers are following Honeywell guides.
Not a criticism just an observation.
Great , clear info . Would like your thoughts on the best way you would use to balance the returns if say downstairs is bigger than upstairs . Thanks for taking for a great presentation.
Great video, one question if one zone is an underfloor zone with an additional pump would you take the sw live from the zone valve?
UFH pump is connected to the thermostat for that zone, so it only runs when that zone requires heat. Thermostat 3 in the diagram, which is also the brown wire for the valve.
John! How might this work if i then introduce a 3 way zone valve for hot water in if we were using a system setup?...
It doesn't. No one should be installing new Y plan / 3 port valves, they are only suitable for a system with hot water and a single heating zone, nothing else.
To add more zones or a hot hot water cylinder, it's another thermostat and a 2 port valve.
Other videos covering those: th-cam.com/play/PLVsHvs2Suqmr5HtxgbInR4bXmH0kLseWc.html
Hi John, great video can you help on external 3 channel programmer to Worcester gas
Thanks
John
Hi John I have a Greenstar combi CDI with comfort 11 RF installed, following your diagram to the letter.
everything plumbed and wired.
Looking at the boiler wiring I find that LS is linked to LR so I am now stuck as when to put the orange wires from the 2 port valves.
The link is removed, the orange wires connect to LR.
The link is there so that the boiler will run all the time when heating is selected on the front panel, it's intended for testing purposes only when the boiler is installed.
Diagrams and instructions are very precious and clear I wonder if there are any possibilities of wiring zone valve and 3 port motorised valve in a single wiring centre. While I was on unvented course the instructor told me we could wire two different valves but I like to know how. It will be very grateful if you could made such video please?
Thank you JW
www.flameport.com/electric/central_heating/heating_wiring_Y_plan_unventedHW.cs4
@@jwflame cannot thank you enough for that Sir.
It'd be better with ONE 3-port valve instead of 2 two-port valves. Quite possibly in upstairs downstairs case, heating on both likely not necessary. If they are both needing heat, another switch is required to allow the 3-port valve to return to its mid position.
On a 2 zone combi system. Could both valves be removed and pipe work bridged where the valves are removed and a simply receiver and stat be added directly to the boiler for call for heat without altering any other pipework?
Yes, it would just end up as a standard combi boiler installation.
Thank you mr ward
Brillant video , thanks . I am in a process of connecting an UFH ( zone 1) and radiator system (zone 2) I am using 2 2port valves as the UFH is only 1 large room , 2 hive thermostats , I am struggling to understand where to wire the UFH pump . any videos of yours available on that subject ?
For a single UFH zone, the pump is wired to the thermostat switched output, so it runs at the same time that the valve is open. Terminal 7 or 8 in the diagrams in the video.
@@jwflame many thanks it makes perfect sense
Do the end switches “make” if you have no power and simply push over the lever to manually open the valve?
No. The manual lever only opens the valve partially, should only be used when filling or draining the system.
Can you add the open therm wiring for one of the valves in a 2 zone system
As far as I know, opentherm would not be possible with a multi-zone system, as opentherm takes over control of the boiler (opentherm is a digital connection that goes straight to the boiler from the thermostat)
JW, cheers your videos are fantastic. I have a question if I may. My boiler doesn't appear to have a switched live. I currently has a link in place labeled ROOM STAT/TIMER. My boiler is constantly firing up even though the thermostats are off. Have you seen this before?
That link is supplied with the boiler, so it can be powered up immediately after installation without having to connect external timers or thermostats, mainly so that the gas side of things can be set up properly. Normally that link is removed, and it's those same terminals where the room thermostat or other controls are connected.
However some boilers have multiple options for connecting external thermostats, so you will need to check the installation instructions for your particular boiler.
Nice explanation
How would I remove the second zone? We have a very small second zone in our bedroom and ensuite that we do not use as the thermostat makes a big CLUNK when it turens on or off and wakes me up! I'd rather have the entire house come on and off together.
Find the brown wire for the zone valve in the wiring centre and connect it to the brown wire for the other zone valve. They will then both work together from the same thermostat.
Fantastic video, thank you. Would it be possible to use a 3 port valve instead of two 2 ports?
Not without extra components and thermostats which had both on and off connections.
3 port valves were designed decades ago for one type of installation - a hot water cylinder and a single heating zone.
They are of little or no use for anything else.
Hi sorry to be i bit cheeky John I'm stumped I have been searching for a wiring dia. for a system with Keston c40 with two switched live, one for heating and other hot w. I had an oversized cylinder made up with a solar coil and heating coil high and low immersion bosses and used it in an extension I built so have two cylinders now, I have two heating zones two-pipe and underfloor with Danfos radio linked stats with their own timers built-in, I want all four zones independent and I am ok with two programmers, any idea where to look for guidance, been in the heating industry for 30 years but pulled a blank on this one. I'm retired on ill-health for some years so out of touch with colleagues to draw from, any help will be appreciated Cheers Mike R.
Hi , I have this system , I have 2 ESI programmable room stats . I would like to put open therm connected to my system , any idea what would be involved to do this , thanks
Opentherm with multiple thermostats is not possible to do unless they are wireless ones that share a single receiver (as opentherm uses digital communication between the thermostat and boiler, and it isn’t designed to allow multiple thermostats, with wireless thermostats, only 1 wireless receiver can be connected to the boiler using opentherm, and you cannot wire a second thermostat/reciever up without getting strange behaviour, such as the boiler only running when BOTH thermostats are calling for heat, or the boiler only responding to one thermostat, or perhaps even the boiler showing error codes and/or not responding to either thermostat)
hi John. thanks a lot, helpful stuff. The plumber has attached an extra Wilo Para pump to the zone 1 side (to help with underfloor heating). Would I attach the live (of the pump) to number 9 in the wiring centre? (the pump only has L,N and E) That way, it would come on when called for by thermostat receiver 1? or is the incorrect? anyway else could help too? thanks
No, if connected to 9, that pump will run when the boiler is on regardless of which thermostat is used. If it's for zone 1 only, connect it to 7, which is the switched output of that thermostat only. Numbers refer to the diagram in the video, your installation may have a different arrangement.
The UFH pump should be part of a manifold with a mixing valve, so it only pumps water for the UFH, and nothing else.
@@jwflame thanks a lot 👌🏻
Thank you Mr John for clarifing and simplifying. I have a question. Do we need a programmer? Just thermostat enough? And what about hot water how it is controlled for each zone? Many thanks
The arrangement in this video would be used with modern programmable thermostats, which have both time and temperature settings. it would be possible to use a separate programmer/timer and thermostat but there is no point - it would cost more, be more complex to install and provide worse control of the heating.
There is no control of hot water here - combination boilers heat the hot water on demand.
Other videos in this series cover hot water controls, th-cam.com/play/PLVsHvs2Suqmr5HtxgbInR4bXmH0kLseWc.html
@@jwflame thank very much Mr John
This is a great overview. One thing that's always confused me (as a lay person), is the circuit route (thermostat -> wiring board -> boiler) carrying the actual power for the boiler itself? Or just enough power to 'activate' the boiler, which then draws running power from an independent connection?
The thermostat is just an on/off signal to the boiler. Also note that this wiring is intended for gas or oil boilers, so the electrical power used is only for the pump and controls, typically under 100 watts.
Electric boilers do exist, they would have a separate high power connection for the heating elements, with the thermostat wired as here, just for on/off control.
@@jwflame Thanks. I actually forgot it's gas combustion that's heating the water, not electricity!
@jwflame hi do you have a video on a combi boiler with ufh manifold & room stats
Hi great help you are!
If I had an underfloor heating pump how would I wire it in? If it’s 3 core without it being on all the time?
Thanks
E&N to the earth and neutral terminals. L to the switched output of the thermostat (3 in the diagrams, also the same as the brown valve wire), so the pump only runs when heat is required for that zone.
@@jwflame thanks mate
Will this working with wireless receivers/thermostats??
Hi Quick Question , If Zone 2 was a UFH system ( pump & Actuators ) would i attach their 230v Power To point 8 ? on the diagram . So they would switch off when the Hive is turned off ? .
Would this also work if Zone 1 and 2 was on at the same time and i turned off the UFH/Zone2 ( would the Pump and UFH turn off ) ( I assume they wouldnt be getting any power from the orange ? )
I have the same question.
@@robday3968 Rob , I converted my single zone to dual zone ( UFH and Radiators ) last weekend . From my UFH wiring i had a Brown & Grey wire ( Brown Sleeve ) . These both connected to point 8 on the diagram . This then meant the pump and actuators turned off with the zone . My setup was using two Hive thermostats .
Sir, what type of cables be used in boiler electrical wiring, please. Thank you.
Heat resistant PVC flex, 0.75mm² would be the usual choice. 3,4, or 5 cores depending on what is being connected.
I've a buffer thermal storage tank. I need to turn on a load when top stat drops to 45c and not turn off until bottom stat reaches 50c. Can anyone tell me what device I need to do this? tia
Is it possible to have a 24v thermostat connected to the zone valve controlling the radiators and a 230v stat connected to the zone valve controlling the u/floor heating on the same combi boiler?
It’s a valliant combi.
I’m pretty sure I can but just wanted some reassurance 😁
If the 24V thermostat just uses 24V for power and has volt free contacts, then it could be used, the thermostat contacts would switch the 230V for the zone valve as in the video.
If the thermostat switched output is also 24V, then it would would require a relay with a 24V coil, the 24V thermostat would power the relay coil and the relay contacts would switch the 230V power to open the valve.
In both cases the thermostat would require a 24V supply from somewhere.
@@jwflame thanks for the reply, keep up the great work 👍🏻
That’s a great video thank you. Would it be the same for underfloor heating zone valve instead of two central heating zone valves? If so how would I connect the pump wiring?
Many thanks
The valve is the same. If it's just a single zone, the pump is wired to the switched output of the thermostat, the same terminal as the brown wire to the valve.
For systems with multiple UFH zones, a separate UFH controller would be used, which will have connections for the pump, actuators and thermostats.
@@jwflame thanks very much John much appreciated
Hi if one zone was underfloor heating what would pump be wired to?
UFH has it's own pump, which for a small single zone would be connected to the thermostat for the UFH.
For larger installations with multiple zones, the UFH pump is connected to a dedicated controller/wiring centre for the UFH together with the thermostats and zone actuators.
Hi, I have this type of set up on my system. But I cannot control zone two independently. Boiler receives the signal, the burner starts and goes off quickly. Valve 2 is opened but I have no flow inside radiators. CH flow is hot but CH return is cold. But when zone 1 calls for heating both zones are heating. Any clues?
If this is a new problem then most likely is a blockage or air lock on zone 2 somewhere.
If it's always been like that then incorrect pipework is also possible.
It has been always like that.
The idea is that from boiler outlet when zone 2 asks the water doesn’t leave. It is cold. Only when zone 1 kicks in outlet is hot straight away
And wire 9 is always live. But boiler is not working