Can someone explain thermostat settings (on wall and individual radiators)

[posey]

I have moved to a new house and don't know how to control the temperature properly.
We have a wall based thermostat (as in my previous place) but also have radiator controls in each room.
If I find say the living room is too hot do I alter the wall thermostat or the individual one on the radiator?
I'm really not sure what works best but don't want to be stung with an enormous gas bill because I've somehow been wasting heat.

Thanks for any help

all my radiators are on the highest number and then i control heating temp on the wall thermostat. Its on 18.5 atm

The thermostat on the wall controls the whole system, but only measures the temperature in the room where it is. So if your wall thermostat is in the hallway and set at 20 degrees, once the hallway gets up to 20 degrees, the whole system will turn off. The thermostats on the radiators control the amount of heat that each radiator puts out (so long as the heating is on - i.e. so long as the temperature you've set for the wall thermostat hasn't been reached). The main advantage of thermostats on radiators is that it means you can turn them down in rooms that you're not using or don't want as hot as the rest of the house. Obviously best to keep the doors to all the rooms closed if you're doing this though.

If the living room is too hot and the rest of the house is comfortable, then turn down the control on the living room radiator. That will make it shut off when it gets warm even when the wall thermostat is still asking the system to pump heat round the house in general.

If you turn down the wall thermostat then it will shut off the whole system quicker and all the rooms will stay a bit cooler than they are now. Even if one radiator says that room is cold, if the wall thermostat thinks it is warm enough then the system won't come on.

Thank you very much, most helpful