Correct Central Heating setup - Thermostat + Radiator TRVs

[bigup]

Hi all

im just reviewing out central heating system and was wondering if you can help with tell me which way i need to set it up to work efficiently

we have a Worcester 37cdi Bosch Gas Combi and a Honeywell CMT927 wireless thermostat, all the rads in the house have TRVs (minus the 2 bathroom rads which do not)

the way its currently setup is, the Boiler is set to number 5 (60 on the digital dial), The room thermostat set to 21C with timer and the Rad TRVs set to 4 or 5. Detached house with total 12 rads

we have a very busy household and there is always someone at home during the day, ( elderly parents, wife+baby), so the thermostat is set to near enough 21C all day long and lower over night

the room thermostat is in the downstairs hall way, the hall way has a radiator ( i know it shouldn't have a TRV but it has and is set to max )

now the way i think it works is, the thermostat tells the boiler to fire up maintain 21C in the hall way. In turn all the rads will warm up and will switch off until it reaches whatever the temp number 4 is on the TRVs. or if the TRVs set to 5, it will only heat up to 21C because the room thermostat over rides this.

is this the correct way of having it? ive read that people set the room thermostat to 25C, then adjust the setting on the boiler so it controls the temp and ive also read the room thermostat should be in the room most used, ie the lounge.

so im a bit confused

any experts out there want to shed some light please?

thanks in advance!

 

[D_Hailsham]

the room thermostat is in the downstairs hall way, the hall way has a radiator ( i know it shouldn't have a TRV but it has and is set to max )

It doesn't really matter if the room stat is in the hall or the living room. You have done the right thing by setting the TRV to max.

Setting the stat to 25 and then lowering the boiler temperature is madness. The boiler will just run continuously in a vain attempt to get the room up to 25.

the way i think it works is: the thermostat tells the boiler to fire up maintain 21C in the hall way. In turn all the rads will warm up and will switch off until it reaches whatever the temp number 4 is on the TRVs. or if the TRVs set to 5, it will only heat up to 21C because the room thermostat over rides this.

You are basically correct. The wall thermostat controls the whole system, so it needs to keep the boiler running until all rooms have reached the required temperature. If this doesn't happen some rooms may never reach the temperature set on the TRV. I had this problem many years ago when the hall rad was very large as it was supposed to heat the hall and the stairwell for a three storey house. I solved the problem by closing down the valve on the rad so it gave off less heat and the hall took longer to heat up. In your case you would have to closed down the lockshield valve.

Setting different temperatures in the rooms only works if you keep the doors closed.