Do I need a room thermostat?

[digger97]

Hi,
I've just had a new combi boiler fitted to replace an older type of boiler. The engineer who is Corgi registered also fitted TRVs on all radiators and removed the room thermostat from the hallway. He said we did not need the thermostat as the TRVs should control the temperature of each room okay. I'm not sure if this is correct or should it be the radiator in the hallway has no TRV and is always on with the room thermostat also in the hallway?

Thanks
Digger

 

[jj4091]

Not an expert, but I was under the impression that all new boilers had to be controlled by a room stat under some regulation or other(corgi or building). Having just fitted a room stat to our system that only had trv's i can say that it seems to be much more efficient & controlable as I have used the radio type with a sender that can be moved from room to room.

 

[mrgas]

Should have a roomstat to act as an interlock and inform boiler when house is warm enough.

 

[namsag]

What combi is it because not all need a room stat to meet regs

 

[methaneman75]

take trv off of hallway rad and get monkeyboy back to fit room stat as you need a control to switch the boiler off electrically and not just have boiler stat /potentiometer cycling off/on all the time

 

[digger97]

The new boiler is a Worcester Greenstar 24i Junior.

 

[gas4you]

Yes you will need a roomstat to comply with Part L regs.

Only boiler at present (that I know of) that the manufacturers state doesn't need one is Vaillant, when you fit the VRC400/430 weather comp direct to the boiler.

 

[Corgigrouch]

Yep, you need a room stat with that boiler. Worcester do a nice little RF programmable room stat that can be fitted in minutes

Namsag, I'm struggling to think of a situation where you would not need a room stat... Gimme a clue.

 

[namsag]

Suggest methane man and mrgas read up on what the regs are before slagging the installer as it is perfectly within part L regs for certain boilers to be fully trv`d with no need for a room stat.
Check what an interlock is.
So best to find out what boiler it is first

As it happens your boiler does require a roomstat and and he should have fitted one in a room without a trv on the rad in that room

 

[namsag]

Corgicrouch where a boiler has a flow switch when the trvs shut the flow switch shuts boiler down .
Baxi 133 HE combi and baxi soloHE .

Have a look at MI on www.partsarena.com/baxi.

The regs ask for an interlock the most common way is a roomstat but not the only way

 

[Corgigrouch]

Thanks for that Namsag.. Because a room stat is the most common form of interlock, it is easy to overlook other possibilities.. Since I only fit worcesters and vaillants as replacements for boilers that I have to condemn (The bulk of my work is repairs and servicing), it is rare that I get to consider anything other than a room stat

 

[namsag]

No prob CG its one of those things that most overlook . As they are few and far between i think some suprimas also have them
Even the guy who took my part L course had to change his notes when it was pointed out to him.

 

[digger97]

Okay guys. I'm getting the impression that my situation is quite unusual but what the guy did was okay so he obviously does know his stuff. Thanks for all your time and info.

 

[namsag]

No read what was put YOUR boiler needs a roomstat and he has done it wrong

 

[digger97]

Sorry, it's hard to keep track. I missed a sentence at the foot of your earlier post. The interlock stuff threw me off. Thanks again.