Room thermostat, what’s the point?

[John.g]

I have mine, a fixed, digital type with 0.3C switching differential, in our combined dining/living room, set to 18C/19C during the day from 0700 to 1900 and normally 21.5C/22C from ~ 1900 to midnight, when/if we go out during the day we just press a button to change it to 17C.
All the remaining rads (also) have TRVs, kitchen set to give 19C, bedrooms 16/17C. Hallway 18C.

 

[Uncle Nick]

I have mine, a fixed, digital type with 0.3C switching differential, in our combined dining/living room, set to 18C/19C during the day from 0700 to 1900 and normally 21.5C/22C from ~ 1900 to midnight, when/if we go out during the day we just press a button to change it to 17C.
All the remaining rads (also) have TRVs, kitchen set to give 19C, bedrooms 16/17C. Hallway 18C.

Thanks for the reply.
Does those settings not mean that the boiler will be on, trying to heat to 18/19C or 21.5/22C but the radiators won’t be heating as they’re set at 16/17C?

 

[John.g]

No, the boiler has its own thermostat, set (mine) to 70C, so once the boiler is switched on from the roomstat then it will control the boiler/system water to 70C, the TRVs will control the flow rhrough their respective rads to give their requiredroom temperatures, obviously if the dining/living room roomstat is satisfied then the boiler switches off but because the settings are higher than the other room TRVs then generally these rooms are satisfied before the living/dining room is reached, I have the two rads in the living/dining rooms throttled/balanced as well which helps to achieve this, it works quite well. I would definitely though suggest installing a digital roomstat as it gives very tight control but I wouldn't go for anything too fancy like one with TPI control except that you can disable this feature.
As I said, mine has differential temperature control (set to 0.3C) so if the roomstat temp setpoint is 20C then it should swith off at 20C and switch back in at 19.7C but I've noticed that when the rooms are heated up that it seems to switch in at 19.9/19.8ish and switch off at 20C. I would think that all the well known manufacturers make this type, mine is a (less well known) FantiniCosmi.

 

[Uncle Nick]

No, the boiler has its own thermostat, set (mine) to 70C, so once the boiler is switched on from the roomstat then it will control the boiler/system water to 70C, the TRVs will control the flow rhrough their respective rads to give their requiredroom temperatures, obviously if the dining/living room roomstat is satisfied then the boiler switches off but because the settings are higher than the other room TRVs then generally these rooms are satisfied before the living/dining room is reached, I have the two rads in the living/dining rooms throttled/balanced as well which helps to achieve this, it works quite well. I would definitely though suggest installing a digital roomstat as it gives very tight control but I wouldn't go for anything too fancy like one with TPI control except that you can disable this feature.
As I said, mine has differential temperature control (set to 0.3C) so if the roomstat temp setpoint is 20C then it should swith off at 20C and switch back in at 19.7C but I've noticed that when the rooms are heated up that it seems to switch in at 19.9/19.8ish and switch off at 20C. I would think that all the well known manufacturers make this type, mine is a (less well known) FantiniCosmi.

Thanks for the detailed reply.
I think I understand how it’s meant to work now.
Looks like I’d better get a room stat fitted before the cold weather!