Room stat v. TRVs ???

[bri160356]

My daughter has just moved house recently and her new abode has full gas central heating (it’s not a combi boiler) with a standard copper hot water tank in the airing-cupboard.

All the radiators have new TRVs fitted including the large lounge which has 2 radiators.

However the lounge has a separate temperature control that is wall-mounted, well away from either radiator. There are no other wall mounted temperature controls anywhere in the house.

What will be the function of this wall mounted unit?

Will it just control the temperature in the lounge area by restricting the hot water to the 2 radiators in that room or will it over-ride everything and control the boiler directly?...........which would be odd???

If it does just control the lounge temperature surely it is in conflict with the TRVs ???

Is it best to switch the lounge TRVs to the highest setting and let the wall mounted unit control the room temperature or vice-versa?

Confused.

All replies gratefully received.

 

[ScottishGasMan]

A wall mounted thermostat, should turn the full heating on and off depending on how warm it is in that room. Although It should not be fitted in a room where the radiators have TRVs for the simple reason if you turn those two rads down, then the thermostat on the wall wont cut the heating off at all.

Its building regulations/energy efficiency these days to have a room stat in the house (sometimes two) but they can be a little hard to get right,

I generally say to try the room stat at say 20*c and all the rad TRVs in living areas at setting 3 or 4, and 2 or 3 in bedrooms, then adjust from there till you have a comfortable house. Sometimes that involves leaving the room stat up a little higher to keep the heating on untill all rooms are warm enough, its a comfort control so use it to make you cofortable without wasting excessive gas heating up areas hotter than you need.

 

[bri160356]

A wall mounted thermostat, should turn the full heating on and off depending on how warm it is in that room. Although It should not be fitted in a room where the radiators have TRVs for the simple reason if you turn those two rads down, then the thermostat on the wall wont cut the heating off at all.

Its building regulations/energy efficiency these days to have a room stat in the house (sometimes two) but they can be a little hard to get right,

I generally say to try the room stat at say 20*c and all the rad TRVs in living areas at setting 3 or 4, and 2 or 3 in bedrooms, then adjust from there till you have a comfortable house. Sometimes that involves leaving the room stat up a little higher to keep the heating on untill all rooms are warm enough, its a comfort control so use it to make you cofortable without wasting excessive gas heating up areas hotter than you need.

Many thanks for the reply but I still don’t quite understand the logic of a room-stat in a lounge area being able to switch off the entire system.

Other remote areas of the house could still be cold but the lounge is warm and the boiler switches off because of the setting in that lounge area.

Sorry if I’m being extremely thick, but please expand.

 

[ScottishGasMan]

No you pretty much have it correct.

The idea would be that the radiators are sized correctly for each rooms heat loss so the house "should" heat up evenly. however in most this is simply not true.

without a room stat the boiler would run continiously, energy effieciency regs state that there must be an interlock (when fitting now) (the room stat) which de activates the boiler once up to temp.

however as you correctly stated the room stat closes off the full system dependant on a snap shot of temperature in one area of one room.

Best you can do is turn it up a couple notches to compensate for cooler rooms. Or leave it up full at 30 and just set the trvs if you wish.

 

[ScottishGasMan]

To add, there are systems which would allow independant electronic control over every room, however such systems (the EvoHome) are very expensive and really wont pay them selfves back compared to being a little watchfull over your own heating use

 

[bri160356]

To add, there are systems which would allow independant electronic control over every room, however such systems (the EvoHome) are very expensive and really wont pay them selfves back compared to being a little watchfull over your own heating use

Many thanks for the replies my friend.
Very much appreciated.

 

[D_Hailsham]

Other remote areas of the house could still be cold but the lounge is warm and the boiler switches off because of the setting in that lounge area.

If that happens, it might be worth balancing the system to make sure each rad is producing the correct amount of heat.