Heating starts when the sun shines in the main window.

[mke4442]

Why does my central heating cut in when the room is already warm, when the sun shines in through the lounge window? The control thermostat is in the hall. Thanks

 

[secret squirrel]

Maybe I'm not reading this post correctly or I've missed something.

If your lounge is warm, south facing garden, well insulated etc etc. Your room stat is in the hall which is obviously colder then of course your boiler will fire to warm up the hall, when the hall has reached temperature then it will turn off

 

[mke4442]

Hi, thanks for your advice. You have correct scenario, south facing lounge, warm room, cooler hall where the stat is installed.

Example...If the hall stat is set at say 18 degC and the house is all at just below 18 degC. Then the lounge reaches 22 degC due to sun radiation, why would the hall stat switch on?

 

[secret squirrel]

Because the hall is less than 18.

If you had the room stat in the lounge and the stat set to 18 the hall would be below that, the boiler would not come on until the lounge was below the 18 by this time the hall may be 16 deg.

 

[diamondgas]

:iagree: simples :iagree:

 

[jase158]

this is why you have the thermostat in the hallway, so when opening door the breeze comes in and triggers your thermostat. thermostat can not tell temperature anywhere else except where it is, so if you put it outside will constantly heat home, you put it in the oven and boiler will never fire up. it does not tell temperature in each room

 

[mke4442]

I set the hall stat to 18 degc say. The lounge door is normally open and is close to the hall stat. So both rooms are roughly same temp. When the sun shines into the lounge, it heats it 'for free' and some heat then transfers to the hall warming it up too. So the stat should switch off as the 'free heat' comes through surely? Thanks to all for entering this thread so far....

 

[jase158]

I set the hall stat to 18 degc say. The lounge door is normally open and is close to the hall stat. So both rooms are roughly same temp. When the sun shines into the lounge, it heats it 'for free' and some heat then transfers to the hall warming it up too. So the stat should switch off as the 'free heat' comes through surely? Thanks to all for entering this thread so far....

hmm...

Heat rises and so it goes above door first before transfering to hallway, try getting a thermometer and testing temperatures in each room. Hard to tell exactly without being there. but possibly other things are triggering this.

But I think you are saying, if front room is hotter then rest of house, then your thermostat is somehow trying to heat rest of house to meet this temperature. not possible as far as I know.

 

[mke4442]

I agree that should not happen as the heat which flows from the lounge to the hall should ensure that the hall thermostat switches off, not on. This is contrary to earlier posts. Curious.

 

[CES]

Has this always happened or has it just started to happen? Have you physically measured what the temperature of the hall is when the heating switches on? Do not assume that because the door to the lounge is open then the temperatures will equal out. This is not always the case due to different heat losses etc.

 

[mke4442]

Good response thanks. Next time the sun shines I will carry out a test.

 

[tamz]

Maybe you have a sunvic stat :lol: