TRV - Radiators

Jaykay7

Hi

Does a boiler use more gas to heat all of the radiators? A colleague explained that they have there TRV's turned down in the rooms they hardly use & thus redcues their gas bill? I thought that it would use the same amount of gas to heat all of the rads. Therefore I have all of mine all full all of the time

Also my boiler which is only about 6 months old, Baxi, is always firing up i.e the flame burner switches itself on every few minutes. Is this normal? The temp on the boiler seems to have dropped from 80c when the flame comes on. Is it anything to do with my cast iron rads.

Any help is appreciated.

Thanks

davetrousers

Your colleague is correct about TRVs

WestonDave

The boiler will have to burn gas to reheat the water coming back from the circuit around the radiators. If you have less radiators on, the water will cool less (the radiators are "radiating" out the heat they take from the water), and so the boiler will have to do less work to restore the heat. So if you have rooms you don't use or need to heat it makes sense to turn the radiators down or off.

I would imagine its normal for the boiler to actually fire every few minutes as it detects that the area that heats the water has cooled. When it has got that part back up to temperature it will switch off to prevent overheating. If the system is working very hard it may not switch off much, conversely if there is little heat loss, it may not come on much. That is evidenced by the fact that the temperature shows a drop and then the flame comes on to restore it back up. 80C is very hot though - would make the radiators very hot to touch - could you maybe drop the temperature setting on the boiler down a bit. That might also reduce the cycling (i.e. going on and off)

davetrousers

Does the OP have TRVs on their radiators?