no room thermostat??

kingkano

Hi all. Just moved into our 3 bed semi last week, tried the boiler out and discovered the thermostat in the dining room isn't wired in at all. The wires seem to terminate next to the boiler instead of going into it. Not sure why they didn't wire this in?? It's basically TRVs on every radiator and a mechanical timer switch on the boiler. It seems an ok boiler, has temp controls for rads and hot water, and the timer fitted....

Anyways I realise from other posts I should really get a thermostat fitted. If I get a heating engineer/boiler type person out how much am I looking at for this?? I'd probably like to opt for a digital all in on jobby (replacing the mechanical timer and the old thermostat in 1 swoop). Oh btw I'm in North Kent if the location makes a difference.

I don't spose I'd save anything by getting them to service the boiler at the same time? lol.

cheers in advance

ariba10

When I fitted TRVs to my rads I took out the thermostat.

Why would you want a thermostat?

kingkano

ariba10 wrote: »

When I fitted TRVs to my rads I took out the thermostat.

Why would you want a thermostat?

I thought a thermostat can completely turn off the boiler when there is no requirement for heating. Whereas with just TRVs and a timer, the boiler would cycle on if the temp in the loop drops a little, even if the rooms are warm enough (trv's arent the most accurate things around).

Am I wrong?

ariba10

A room thermostat works on the air temperature in the room it is fitted in.

You could be in a situation where the room it is in is warm but some or all of the others are cold, or the other way around. I cannot see the point in having both

payless

I was told you need both ( well no TRV needed for area where thermo placed - often hallway ) for reasons explained by KK

ariba10

Once the room stat cuts in it makes all the TRVs useless.

Canucklehead

Hi

Is your boiler newish? If you go to the manufacturers web site, have a look for controls .You might be able to upgrade your timer for a digital one or maybe a wireless system.
If not then have a look at say Drayton for wireless programmable room stats.

HTH

ariba10 see http://www.energysavingtrust.org.uk/uploads/documents/housingbuildings/ce30.pdf

As said it is a requirement to have boiler interlock,ie roomstat.

Corgi Guy.

Snow_Dog

You said there are trvs on every rad, isnt there supposed to be one left without a trv for there to be a minimum volume flow when the boiler is running.

kingkano

Its a Radiant RBS 20 e Midy - I estimate about 7yrs old. Which seems to be manufactured by an italian company?

Yes every rad has a TRV. From reading I think the room with the stat should be TRVless. I guess because the previous owners didnt have a roomstat they just used TRVs on everywhere like ariba10 does.

Boiler interlock (see Section 5.1) is needed to ensure that the boiler is
switched off when neither heat nor hot water are wanted.Thermostatic
radiator valves (TRVs) alone will not provide a boiler interlock.These must
be supplemented by a room thermostat or other device to prevent

unnecessary boiler cycling.

Interesting...

kingkano

btw whats there but not wired in so it seems is in fact this

Canucklehead

Hi... if you don't have the manual for your boiler here is a link http://www.radiant.it/eng/pro_dati.php?oprod_idprodotto=93 details should be there about wiring in external controls or would be available by contacting Radiant (not familar with the brand). It is possible the reason it is not connected might be a DIY cable incident or previous owner didn't see any need for room stat;)

Corgi Guy