One cold bedroom in a zone

Ltec · Oct 11, 2020

I have 3 bedrooms in a zone. The main bedroom has an electric thermostat on the wall and the other 2 bedrooms has trv valves.
The main bedroom can be controlled ok with its electric thermostat and the second bedroom is too hot so I've turned the trv down. It needs a little tweeking but I think its OK but the third bedroom is too cold even with the trv open full.
I think the main bedroom is heating up quicker and then turning the whole zone off and not allowing it to heat up properly.
If this is the case, what are my options?
Do I need a bigger radiator in that bedroom to heater it up quicker than the main bedroom?

Chuck · Oct 11, 2020

Ltec said:
Do I need a bigger radiator in that bedroom to heater it up quicker than the main bedroom?

Maybe but you can probably adjust the lockshield valves on the other rooms to reduce their share of the heat and boost the amount getting to the cold room. The adjustments will be quite sensitive. When you are close to 'correct' you'll need to make changes in steps of 'hours', i.e. 1/12th of a turn. Search this site or Google 'balancing radiators' for detailed instructions.

You only normally need to increase the size of a radiator if it is getting nice and hot but the room is still too cold.

Aquarius · Oct 11, 2020

Does the bedroom with the electric thermostat have a trv on radiator?

Ltec · Oct 11, 2020

Aquarius said:
Does the bedroom with the electric thermostat have a trv on radiator?

No. Just 2 of the wee valves to slow down the flow. I've just tightened 1 in a bit to see if more flows to the other bedrooms tonight.
Does new builds still need radiators balanced

Aquarius · Oct 11, 2020

Ltec said:
Does new builds still need radiators balanced

Not generally unless it wasn’t done correctly or you have taken one off for decorating for example.

Chuck · Oct 11, 2020

@Ltec - May I ask why you marked my post 'disagree'? Is it not a correct answer to your question, or at least the specific part I quoted? I also gave you a low-cost low-risk possible solution.

Ltec · Oct 11, 2020

Chuck said:
@Ltec - May I ask why you marked my post 'disagree'? Is it not a correct answer to your question, or at least the specific part I quoted? I also gave you a low-cost low-risk possible solution.

Sorry I didn't know i did. I didn't even know their was such a thing. Thank you for answering my question and you were first to respond to me. I forgot that radiators could be balanced so hopefully that will sort it.
My phone goes crazy on this website with adverts flying everywhere. I have to search between adverts to try to see answers.
I think the disagree is off the post now.

Chuck · Oct 11, 2020

Ltec said:
I think the disagree is off the post now.

Many thanks.

Something I should have mentioned in my original reply was to check that the cold radiator isn't full of air (or hydrogen). If it's colder at the top than lower down, try bleeding it. It's not clear how old your system is or how long there's been this problem but new systems often need to be bled and topped up with a small amount of water via the 'filling loop' a couple of times over the first few months of operation.

Alan Wright · Oct 13, 2020

Hi Ltec,

I have been selling radiator flow boosters for years and I have just launched a new version as well.

Either version should solve you problem if you find it impossible to get what you want by just balancing flows via turning valves down.