Hi Derek, i've just started watching your videos and think they're great. easy to follow and the way you explain things makes it sound simple so i hope you don't me posting a couple of questions which will hopefully help me better understand my home system. i have a pressurired system with ten rads, 6 upstairs and four downstairs. all have trv's on the feed and lockshield on the return with the exception of a towel rail that has lockshields on both sides. the pump is in the garage with the new tank and Logic Max Heat 18X boiler. I recently discovered that the trv's on 4 of the upstairs rads were installed on the return and i also noted that there wasn't a balancing valve on the HW coil return (which is shown in the boiler manual). I installed a balancing valve in the HW coil and swapped over the trv's and lockshields on the 4 rads yesterday, bled the system and all fired up lovely. i then checked with Grundfoss to ask which would be the best setting for my pump, they advised the proportional pressure setting, either 1 or 2. i tried this and thought all was ok until today when we ran out of hot water (the house is full of women) so i sprang into action on the HW only setting but after 30mins the water wasn't even lukewarm!! i can only think that the balancing valve "throttling effect" was sensed by the pump forcing it to slow down so much that it didn't heat the water so i changed the setting to constant pressure 1 and the water heated fine, and the heating which is on at the moment seems fine also. so my questions are..... could it have been the return temperature back to the boiler that stopped the HW only from heating the water or was it the pump sensing back pressure therefore slowing wverything down to nothing or, could it be something else??? All this started because i want to ensure my system is running as efficiently as it can so we're not throwing money down the drain, the bills are horrendous??? any help Derek would be greatly appreciated. Mick Kitcher-Chesterfield.
This is by far the worst of his videos I've watched tbh, I'm a heating engineer and this video explains almost nothing regarding how to balance a system, the vast majority of the vid has got nothing to do with it
I’ve seen some vids with interest….I’ve just added WC to my older Viessman 200 and it’s screwed up my UFH temp ….I’ve set curve to 2.2 now and rads get super hot but still very low UFH….any clues ?
I bought one of those digital thermometer 10 years ago to Balance a system in a house that i bought couldn't get it to work. But recently i used it to set my automatic bypass valve and it worked a treat. I also check my system which i balanced it was give the correct delta T across rads and boiler i was surprised i balanced the whole system without anything. I guess u get years of experience to know how to balance a system
At what flow temperature should you balance your radiators? Considering the laws of thermodynamics, the room temperature should affect your deltaT during the balancing process, which will be ever-varying during the process - the room is warming up. The radiator should reject more heat to the atmosphere in a colder room. So at the time, with an inlet (flow) temperature of 70oC, your rad exit (return) temperature might be 50oC in a colder room (deltaT 20), but 60oC in a warmer room (deltaT 10). The radiator efficiency would also affect this - an aluminium radiator with a much higher fin count should reject more heat and at a higher rate than a traditional iron rad. So using temperature to measure the flow characteristics of a radiator - to ascertain system hydraulic balance - is flawed. Thoughts? Also a thought on boiler flow and return temperatures - if your system can support a radiator deltaT of say 20oC, in that the flow rate ensures all radiators get sufficiently hot, your boiler return temperature will be indoubtedly lower. So at 70oC flow you may see 40oC (deltaT 30) - is it a case of the bigger the number (deltaT) the more efficient the boiler (better)?
Agreed that temperature is a blunt instrument to measure flow in a system but I suppose if there was a resounding need to measure flow rates at the rad valves it'd exist on the market and be popular. Which it isn't. Suspect you're a bit of a refrigeration engineer throwing what you know into the dark art of heating... On your second point about delta T & efficiency, the magical 20 degrees difference is aimed for but the best thing would be to research your specific boiler, the manufacturer might provide efficiency curves but what can you do with that information anyway?
I'd do it at full temperature, as you say, if it's a 30°C day you're not going to tell the difference between a pipe at ambient room temp or a 30°C return. Tbh I feel the first half of this video has nothing to do with balancing as far as I can see
I have watched only half way through and I already like your video that explains not just how to trim the valves on each rad, but and some mathematics behind. As a not professional plumber I have another question now. What the theory behind about how boiler condensate regarding the Delta T? Probably I need more theory on how boiler works in mathematical way, not that it heats the water? Have you video about that?
@@andrewmillwardwatford9410 YES ! I've 5 zones in my house: 1.DHW 2. Bed 1 3. Bed 2 4. Bed 3 5. rest of house - on TRVs No lockshield valves on anything. Works great. Z 5 in 15mm pipe. the rest 22mm When Z 5 is on, designed leaks keep the rads in the kitchen & bathroom top inch hot - for towel drying. An auto bypass valves tries to keep the boiler happy. The TRVs control water flow - so no need for 'balancing'.
Interesting video as having replaced all my rads in the past 12 months, I've been trying to learn how to correctly balance them. My question is, when did you turn the lockshield valve 'virtually off'? At 23:20 you fully opened it and then went to set the boiler to maximum output temp. But at 25:20 when you've found a deltaT of only 5degC across this rad, you said you'd virtually turned it off. Can you clarify this please?
Hot water cylinder needs to be 60-65°C to avoid 'bugs' (e.g. legionella) from contaminating the supply. Lowest temperature for rads is where they don't get hot enough to keep the rooms as warm as you'd like. If you can turn the boiler down to 40°C for heating the rads and the rooms are as warm as you like, you'll have nearly as efficient heating system as you can get. Think about it - loss of efficiency is when the heat is being sent straight outside - i.e via the boiler flue. So the colder that is, the more heat you're keeping in the house !
very good just done 4 rads and trvs , some have locksheilds like kitchen as its too small for a trv, just need too flush 3 rads and add inhibitor so watching theses vids as there getting allot hotter sice ive flushed all the other rads , so i need to get my head around this even with the ones with no locksheilds
How cold do you want the place ? A rad can't be too big as it can always be turned down whereas a too small rad can't be turned up ! In my main rooms, I have 3-panel rads 70cm tall by 2m in length. They've not been fully 'on' ever as we've never left the house at Christmas and turned the heating off. But if we did and got home in the new year and the place was down to 5°C Those big rads would soon get the place warm again - which is what you want !
I'm a little confused about the l/s closing down of the rads. Take an extreme example and we shut all l/s down to a 1/8 turn, surely the water going back to the boiler would be fairly quick and nearer the boiler set flow temperature than, say, all l/s open half way. Why not open fully all l/s and let the rads fill and convect heat out? What I'm trying to say is, is there a point when the l/s not being open enough is just as bad as the l/s being fully open?
Great video. Looking forward to part 2. This might sound like a silly question but I have to ask. What has the outside temperature got to do when balancing radiators? Thanks Derek 👍🏻 Asian Jon. Training.
@@mj0n4id36 Sadly, he and all heating engineers are clueless. In a multi-storey building (i.e. typical house), most radiators should be fitted with Thermostatic Radiator Valves (TRVs) so that the various rooms can be controlled individually. The concept of 'balancing radiators' does not apply to radiators fitted with TRVs as the TRVs deal with the balancing.
On the job, there's never enough time. If I've just fitted new rad, I'll fill system , turn heating on full, then go around house , starting upstairs. If rad is boiling I'll turn lockshield off ,then open couple turns . I'll do this upstairs, then down. Many homes ,I find upstairs are always red hot. Down are less hot. After feeling all rads, I'll then open or close accordingly , cracking open hot rads few turns, and opening up colder rads. Basicly restrict or persuade water to flow where I need it to. I never get bogged down into technical stuff. And never use a thermometer. If.my new rad Is cold I'll turn all rads off and wait until hot ,then reopen fully.....then me go bye bye...... Fyi? Then I'll get called back to a vertical designer rad, cos water won't circulate around it ffs! Bloody things! Inlet ....outlet.....top....bottom.....sick of those buggers🤣
good luck with that mate .. are you trying to achieve a stable room temperature or a stable radiator temperature, I think the best you're going to get is a reasonable compromise. In practice the only way it works is by manual intervention, quite often people just use the room stat to turn the system on and off, this is mostly done by the lady in the kitchen cooking dinner.
My Viessmann 200 installations work between 55c flow and lower delivering accurate room temperatures of plus or minus 1c Using Viessmann weather compensation. Radiators originally designed for Dt 50 are working at 55 35. Remarkable boilers give remarkable results.
@@andrewmillwardwatford9410 What's your DHW temperature ? What's the diff between the 100 and 200 ? Do you know anyone making third party boards for Veissmann ? Mine's set for 68°C as there's only 1 thermostat - and that's for the DHW. So rads are hotter than they need to be for the general house space. Also, the idiots that made the boiler have the flue coming out of the top - how stupid !
@@millomweb dhw 50c with Legionella cycle once a week. I have a flow temp of 42c at 9c outside temp at this moment. Perfect room temperature but needs to be well balanced as trvs are not really functional on this system.
@@millomweb don't know any third parts boards. Almost never get faulty boards on Viessmann so demand is low. Just as well as a quality Viessmann board comes with a quality price tag.
Digital thermometer probes on every rad flow and return (wife goes mad! Says I'm obsessive!). Lockshield valves are poorly designed. 1 turn is damned near full flow. Bathroom towel radiator is worst to balance. To get it hot you basically end up with little temp difference. Presumably mass of pipes takes longer to transfer heat than a normal rad.
Your right 1 full turn is pretty much fully open, in my experience most locksheilds are useless at restricting the flow once you exceed half a turn. I have noticed towel rails seem to take longer to start up than normal rads but they also stay hotter for longer so I can only think it's down to different material?
@@nrg-5003 I think towel rail rads have much thicker metal. I imagine lockshield settings could be affected by any debris or swelling of washers over time, since they are just cracked open
Hi Derek, i've just started watching your videos and think they're great. easy to follow and the way you explain things makes it sound simple so i hope you don't me posting a couple of questions which will hopefully help me better understand my home system. i have a pressurired system with ten rads, 6 upstairs and four downstairs. all have trv's on the feed and lockshield on the return with the exception of a towel rail that has lockshields on both sides. the pump is in the garage with the new tank and Logic Max Heat 18X boiler. I recently discovered that the trv's on 4 of the upstairs rads were installed on the return and i also noted that there wasn't a balancing valve on the HW coil return (which is shown in the boiler manual). I installed a balancing valve in the HW coil and swapped over the trv's and lockshields on the 4 rads yesterday, bled the system and all fired up lovely. i then checked with Grundfoss to ask which would be the best setting for my pump, they advised the proportional pressure setting, either 1 or 2. i tried this and thought all was ok until today when we ran out of hot water (the house is full of women) so i sprang into action on the HW only setting but after 30mins the water wasn't even lukewarm!! i can only think that the balancing valve "throttling effect" was sensed by the pump forcing it to slow down so much that it didn't heat the water so i changed the setting to constant pressure 1 and the water heated fine, and the heating which is on at the moment seems fine also. so my questions are..... could it have been the return temperature back to the boiler that stopped the HW only from heating the water or was it the pump sensing back pressure therefore slowing wverything down to nothing or, could it be something else??? All this started because i want to ensure my system is running as efficiently as it can so we're not throwing money down the drain, the bills are horrendous??? any help Derek would be greatly appreciated. Mick Kitcher-Chesterfield.
excellent video - cannot wait for part.I think we are missing this basic, elementary knowledge on daily bases.
Great - especially like the way he looks into space when telling you something, as if he's thinking "am I right saying that?"
This is by far the worst of his videos I've watched tbh, I'm a heating engineer and this video explains almost nothing regarding how to balance a system, the vast majority of the vid has got nothing to do with it
Should the flow go into the lock shield side or the TRV side ?
@@grahamherron6616 can go either way but the valves have to be installed the correct way they are being used but standard is flow on TRV
I’ve seen some vids with interest….I’ve just added WC to my older Viessman 200 and it’s screwed up my UFH temp ….I’ve set curve to 2.2 now and rads get super hot but still very low UFH….any clues ?
how do you balance rads with operntherm Inest) and moduating boiler?
Wmmi cant find your pipe sizing video can you send me link of that video please
I bought one of those digital thermometer 10 years ago to Balance a system in a house that i bought couldn't get it to work. But recently i used it to set my automatic bypass valve and it worked a treat. I also check my system which i balanced it was give the correct delta T across rads and boiler i was surprised i balanced the whole system without anything. I guess u get years of experience to know how to balance a system
At what flow temperature should you balance your radiators? Considering the laws of thermodynamics, the room temperature should affect your deltaT during the balancing process, which will be ever-varying during the process - the room is warming up. The radiator should reject more heat to the atmosphere in a colder room. So at the time, with an inlet (flow) temperature of 70oC, your rad exit (return) temperature might be 50oC in a colder room (deltaT 20), but 60oC in a warmer room (deltaT 10). The radiator efficiency would also affect this - an aluminium radiator with a much higher fin count should reject more heat and at a higher rate than a traditional iron rad. So using temperature to measure the flow characteristics of a radiator - to ascertain system hydraulic balance - is flawed. Thoughts?
Also a thought on boiler flow and return temperatures - if your system can support a radiator deltaT of say 20oC, in that the flow rate ensures all radiators get sufficiently hot, your boiler return temperature will be indoubtedly lower. So at 70oC flow you may see 40oC (deltaT 30) - is it a case of the bigger the number (deltaT) the more efficient the boiler (better)?
Agreed that temperature is a blunt instrument to measure flow in a system but I suppose if there was a resounding need to measure flow rates at the rad valves it'd exist on the market and be popular. Which it isn't. Suspect you're a bit of a refrigeration engineer throwing what you know into the dark art of heating...
On your second point about delta T & efficiency, the magical 20 degrees difference is aimed for but the best thing would be to research your specific boiler, the manufacturer might provide efficiency curves but what can you do with that information anyway?
I'd do it at full temperature, as you say, if it's a 30°C day you're not going to tell the difference between a pipe at ambient room temp or a 30°C return.
Tbh I feel the first half of this video has nothing to do with balancing as far as I can see
Did you open every rad fully at the end to then take the temperature or were all the other radiators currently off and just this one on?
I have watched only half way through and I already like your video that explains not just how to trim the valves on each rad, but and some mathematics behind. As a not professional plumber I have another question now. What the theory behind about how boiler condensate regarding the Delta T? Probably I need more theory on how boiler works in mathematical way, not that it heats the water? Have you video about that?
I have quite a few videos on boilers guess you will need to watch them all the find out how they work 😜
Balancing radiators is a complete nonsense with a properly designed system.
@@millomweb can you explain
@@andrewmillwardwatford9410 YES !
I've 5 zones in my house:
1.DHW
2. Bed 1
3. Bed 2
4. Bed 3
5. rest of house - on TRVs
No lockshield valves on anything.
Works great.
Z 5 in 15mm pipe. the rest 22mm
When Z 5 is on, designed leaks keep the rads in the kitchen & bathroom top inch hot - for towel drying. An auto bypass valves tries to keep the boiler happy.
The TRVs control water flow - so no need for 'balancing'.
@@millomweb and you think that's good design ?
Thomas Bradwell
Thanks Derek
Interesting video as having replaced all my rads in the past 12 months, I've been trying to learn how to correctly balance them. My question is, when did you turn the lockshield valve 'virtually off'? At 23:20 you fully opened it and then went to set the boiler to maximum output temp. But at 25:20 when you've found a deltaT of only 5degC across this rad, you said you'd virtually turned it off. Can you clarify this please?
I will be doing the full balancing of a system on Wednesday hopefully that will give you all your answers so look out for that
I take it you've little knowledge of how life works - like all the 'heating engineers' and clueless boiler manufacturers.
@@millomweb ?
@@andrewmillwardwatford9410 It seems they've forgotten PHYSICS and what they're trying to achieve.
its very nice video thanks
I have learnt so much...going to screwfix for a laser thermometer....
Best videos on TH-cam are from TomKat. What lowest temperature would you set for cylinder and boiler with radiators as an emitters? thanks
70 oc because I would want the water to recover quickly
Hot water cylinder needs to be 60-65°C to avoid 'bugs' (e.g. legionella) from contaminating the supply. Lowest temperature for rads is where they don't get hot enough to keep the rooms as warm as you'd like. If you can turn the boiler down to 40°C for heating the rads and the rooms are as warm as you like, you'll have nearly as efficient heating system as you can get. Think about it - loss of efficiency is when the heat is being sent straight outside - i.e via the boiler flue. So the colder that is, the more heat you're keeping in the house !
@@millomweb Viessmann heat dhw to 50c with a Legionella cycle once a week.
Great video.
very good just done 4 rads and trvs , some have locksheilds like kitchen as its too small for a trv, just need too flush 3 rads and add inhibitor so watching theses vids as there getting allot hotter sice ive flushed all the other rads , so i need to get my head around this even with the ones with no locksheilds
Hi Derick could you please do a video of sizing radiators in the real world
On the to do list mate 👍🏻
How cold do you want the place ? A rad can't be too big as it can always be turned down whereas a too small rad can't be turned up ! In my main rooms, I have 3-panel rads 70cm tall by 2m in length. They've not been fully 'on' ever as we've never left the house at Christmas and turned the heating off. But if we did and got home in the new year and the place was down to 5°C Those big rads would soon get the place warm again - which is what you want !
I'm a little confused about the l/s closing down of the rads. Take an extreme example and we shut all l/s down to a 1/8 turn, surely the water going back to the boiler would be fairly quick and nearer the boiler set flow temperature than, say, all l/s open half way. Why not open fully all l/s and let the rads fill and convect heat out? What I'm trying to say is, is there a point when the l/s not being open enough is just as bad as the l/s being fully open?
7 degrees in Ashton, must be the height of summer but I bet it’s still raining .. 😉
Always 😂
Great video. Looking forward to part 2. This might sound like a silly question but I have to ask. What has the outside temperature got to do when balancing radiators? Thanks Derek 👍🏻
Asian Jon. Training.
If it is warm outside then the radiators won’t loose their heat so it will be hard to balance
@@tomkatgastraining thanks!
@@mj0n4id36 Sadly, he and all heating engineers are clueless. In a multi-storey building (i.e. typical house), most radiators should be fitted with Thermostatic Radiator Valves (TRVs) so that the various rooms can be controlled individually. The concept of 'balancing radiators' does not apply to radiators fitted with TRVs as the TRVs deal with the balancing.
@@millomweb nonsense !
@@andrewmillwardwatford9410 Which bit are you claiming is nonsense ?
Rads closer to boiler turn quarter of a turn rads further away from the boiler open more it’s not rocket science.
I’m surprised they don’t putting the TRVs at high level is not part of part M tbh.
On the job, there's never enough time. If I've just fitted new rad, I'll fill system , turn heating on full, then go around house , starting upstairs. If rad is boiling I'll turn lockshield off ,then open couple turns .
I'll do this upstairs, then down. Many homes ,I find upstairs are always red hot. Down are less hot.
After feeling all rads, I'll then open or close accordingly , cracking open hot rads few turns, and opening up colder rads.
Basicly restrict or persuade water to flow where I need it to.
I never get bogged down into technical stuff. And never use a thermometer.
If.my new rad Is cold I'll turn all rads off and wait until hot ,then reopen fully.....then me go bye bye......
Fyi? Then I'll get called back to a vertical designer rad, cos water won't circulate around it ffs!
Bloody things! Inlet ....outlet.....top....bottom.....sick of those buggers🤣
I'd suggest you leave it to someone who has a clue.
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good luck with that mate .. are you trying to achieve a stable room temperature or a stable radiator temperature, I think the best you're going to get is a reasonable compromise. In practice the only way it works is by manual intervention, quite often people just use the room stat to turn the system on and off, this is mostly done by the lady in the kitchen cooking dinner.
If you watch the video on Wednesday you will see if I was successful or not
My Viessmann 200 installations work between 55c flow and lower delivering accurate room temperatures of plus or minus 1c Using Viessmann weather compensation. Radiators originally designed for Dt 50 are working at 55 35. Remarkable boilers give remarkable results.
@@andrewmillwardwatford9410 What's your DHW temperature ?
What's the diff between the 100 and 200 ?
Do you know anyone making third party boards for Veissmann ? Mine's set for 68°C as there's only 1 thermostat - and that's for the DHW. So rads are hotter than they need to be for the general house space.
Also, the idiots that made the boiler have the flue coming out of the top - how stupid !
@@millomweb dhw 50c with Legionella cycle once a week. I have a flow temp of 42c at 9c outside temp at this moment. Perfect room temperature but needs to be well balanced as trvs are not really functional on this system.
@@millomweb don't know any third parts boards. Almost never get faulty boards on Viessmann so demand is low. Just as well as a quality Viessmann board comes with a quality price tag.
Tomkat👍🏻
Digital thermometer probes on every rad flow and return (wife goes mad! Says I'm obsessive!). Lockshield valves are poorly designed. 1 turn is damned near full flow. Bathroom towel radiator is worst to balance. To get it hot you basically end up with little temp difference. Presumably mass of pipes takes longer to transfer heat than a normal rad.
Your right 1 full turn is pretty much fully open, in my experience most locksheilds are useless at restricting the flow once you exceed half a turn. I have noticed towel rails seem to take longer to start up than normal rads but they also stay hotter for longer so I can only think it's down to different material?
@@nrg-5003 I think towel rail rads have much thicker metal. I imagine lockshield settings could be affected by any debris or swelling of washers over time, since they are just cracked open
You’ve just wasted 28 minutes of my life I will not get back. Just get to the bloody point.
30% of 70 is 21….mmm.
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