No need for sarcasm merely asking. Clearly wrong I suspect neither trv is bi directional. Take a pic further back to get both ends in
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H
hotdogharry
Funny enough the rad thats not heating properly is the only one with a lockshield valve the other four all have the two of the TRV'S
I think we'd all like to see a pic of one of the rads with two TRV's
Measure the temperature for the flow and return at once, adjust balancing valve until you get a consistent temperature drop across the rad (I go for about 10-12C drop). Measuring the temperatures is the classic way to balance the flows, but a dual thermometer with pipe clips makes it pretty fast. You can use other techniques.
If you want to balance your system, this is a good guide for a DIYer:
Balancing central heating radiators - DIYWiki
W
Welder
Without any images we are scuppared and with the OP's abruptness at our crystal ball not working we may never know...🙄
Sorry Tim but that 'thing' you posted the link to re balancing is a pile of junk. About as professional as my ex wife was faithful 🙁
I apologise for being old, but rads are designed to drop 10 degrees across them. That can be measured pretty darned accurately with your hands. If you can 'feel' the difference in flow & return its about right. Perhaps once you get old you become less sensitive 😉
The rule of thumb for balancing (starting point if more work reqd) is one full turn open on the lockshield for 'big' rads & one half turn open on the small rads.
I take it everyone is aware that once the rads are done then you're looking for 11 deg drop across the boiler so you use the pump speed to achieve that ...🙂
Sorry Tim but that 'thing' you posted the link to re balancing is a pile of junk. About as professional as my ex wife was faithful 🙁
I apologise for being old, but rads are designed to drop 10 degrees across them. That can be measured pretty darned accurately with your hands. If you can 'feel' the difference in flow & return its about right. Perhaps once you get old you become less sensitive 😉
The rule of thumb for balancing (starting point if more work reqd) is one full turn open on the lockshield for 'big' rads & one half turn open on the small rads.
I take it everyone is aware that once the rads are done then you're looking for 11 deg drop across the boiler so you use the pump speed to achieve that ...🙂
Can you explain why that link is wrong?
The explanation omits the need to remove TRVs/fully open each control valve, but I can't see what else is wrong. Trying to get the system losing the same amount of temperature across each emitter, 10 or 11°C on a standard boiler, 20°C or more on a condensing boiler (provided that this does not result in radiators giving out insufficient heat to the rooms) seems to be about right.
What am I missing?
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hotdogharry
Not sure what a pic will show you its the same as pic already posted but on both ends of rad
H
hotdogharry
thanks to all repliers but all I wanted to know was whether I could 'balance' rads using the TRV'S and should I leave one end open and adjust the other or adjust both.
Since asking I have tried turning rads off and the colder rad did get hot so guess I just need to play around adjusting them til i get a sort of balance
Since asking I have tried turning rads off and the colder rad did get hot so guess I just need to play around adjusting them til i get a sort of balance
W
Welder
The fact is, you are going to have the TRVs fighting one another. You will never know which is controlling and worse, you'll not be able to physically balance them becasue both ends may be fully open and 'rob' other rads or both ends might be fully closed. The reality is that you will never ever be able to know what's actually happening and system performance will be - well - sh1te!
To be honest, it is truly a dogs dinner. In your position I would get one end of all rads swapped for a proper lockshield so it can be balanced and then you can get on with life... Sorry.
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hotdogharry
When one valve is closed rad goes cold so just going to try slowly open it until rad gets hot and see if 'cold rad' gets hot enough
Would like to replace all rads pipework but its not an option at moment Any idea roughly how much it would be to replace valves on say 5 rads?
W
Welder
Depends where you live. Around here, I'd have done that for £200-250.
That is because a picture showing the valve from the side should show whether the valves will allow flow in both directions or only one (a cast in arrow- single or double ended).
Trying to balance a radiator with a TRV at both ends is next to impossible, hence the suggestion that you replace one end of each road with a stopvalve.
In case you didn’t know, TRVs work automatically and as you adjust one manually, it is possible that all the others will adjust themselves because of the different heat now presenting itself at their sensors. You may well end up by chasing your tail for weeks.
My theory is that the system was flushed when the new boiler was fitted ( ask the plumber) and this has altered the thermodynamics of the system.
Q for you pros out there...
Do you, as a matter of course, check radiator flow temps after a major change like a boiler, or is that a separate job?
That is because a picture showing the valve from the side should show whether the valves will operate in both directions or only one (a cast in arrow- single or double ended).
Trying to balance a radiator with a TRV at both ends is next to impossible, hence the suggestion that you replace one end of each road with a stopvalve.
In case you didn’t know, TRVs work automatically and as you adjust one manually, it is possible that all the others will adjust themselves because of the different heat now presenting itself at their sensors. You may well end up by chasing your tail for weeks.
My theory is that the system was flushed when the new boiler was fitted ( ask the plumber) and this has altered the thermodynamics of the system.
Q for you pros out there...
Do you, as a matter of course, check radiator flow temps after a major change like a boiler, or is that a separate job?
My plumbers didn't, but I didn't ask them to and I suspect they knew I would do it (may have told them so). I'm happy to pay few-hundred/day to deal with horridly difficult and tight copper pipe routing (and of course GasSafe competency at the boiler end) and also for said folks to take responsibility for any leaks and fix them.
But radiator balancing can take a day to get a completely unbalanced system good (because things take time to heat up and cool down - it's a slow process) - it's a perfect job that *anyone* with a means to measure temperature, a couple of household tools and the ability to follow a simple set of instructions.
You can rough it much quicker - eg I know that about 3/4 turn open on my particular make of lockshield valve gets it "not far off" and good enough to work. I just like to go the whole hog and try to get 10-12C drop on every rad so the boiler return is always <55C for efficient condensing mode to work.
Also you have the problem that it's sometimes necessary to leave valves full open for a bit to blow any air through the pipes where it can be trapped and bled off in the radiator. I suppose in an ideal world, your plumber might have an apprentice who could run around after each job tidying these things up - but most plumbers don't have a lad IME...
But radiator balancing can take a day to get a completely unbalanced system good (because things take time to heat up and cool down - it's a slow process) - it's a perfect job that *anyone* with a means to measure temperature, a couple of household tools and the ability to follow a simple set of instructions.
You can rough it much quicker - eg I know that about 3/4 turn open on my particular make of lockshield valve gets it "not far off" and good enough to work. I just like to go the whole hog and try to get 10-12C drop on every rad so the boiler return is always <55C for efficient condensing mode to work.
Also you have the problem that it's sometimes necessary to leave valves full open for a bit to blow any air through the pipes where it can be trapped and bled off in the radiator. I suppose in an ideal world, your plumber might have an apprentice who could run around after each job tidying these things up - but most plumbers don't have a lad IME...
View attachment 35566
The valve body in this pic is from a Honeywell TRV. The black dial with numbers is a balancing device.
You say you have the same body on both ends of your radiators, but do they both have the same cap? If not, what type of cap is it? Pics would help.
The valve body in this pic is from a Honeywell TRV. The black dial with numbers is a balancing device.
You say you have the same body on both ends of your radiators, but do they both have the same cap? If not, what type of cap is it? Pics would help.
That's highly unusual, can't imagine what the installer was thinking. I would replace one on each rad with a standard iso valve and put the TRVs on eBay to offset the cost.
If you have 2 TRVs the one set to lower temperature will rule, the other doing nothing.
TRVs often have a throttling screw with an offset screwdriver slot, I think I can see it on your pic. Make sure the one on the rad you want warmer is fully open, and throttle some or all of the others. It goes 3 full turns from open to closed if memory serves. It might be time-consuming to get the whole system just right.
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hotdogharry
Thanks for that yes all other rads have the honeywell type with the black inserts with numbers on (been like it at least since I moved in 21 years ago and who knows how long before that) have been trying to balance by just closing one end of other rads til they are cold and gradually opening them very slowly until the heat I think will warm the rooms and it has improved the heat on the colder one . I will try it using the black inserts oneday but for now thanks to everyone and will not be replying in here but will keep an eye on for any further posts THANKS ALL
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