Heating problem ?

Don't want to call anyone out if it's not a fault so thought I'd ask you lovely people.
Gas central heating ..

Over night we leave our heating on 10 degrees it rarely if ever comes on. But last few nights one radiator has heated up in back bedroom.

No other radiator heats up and the one in the room where the thermostat is isn't heating up either.

Obviously I'll call out mr gasman if it's appropriate because it's boiling Gracie having it come on and she like me likes a cool room.

Any ideas welcome.

Re: Heating problem ?

That's an odd one Julie, even if the TRV on the rad is stuck open it still can't heat up unless the boiler is on, in which case all your rads would be on. I assume the timer on your programmer is set to off overnight?

Re: Heating problem ?

Air in the radiators? on the side at the top are key holes and you should have a key for them open slightly
Turning these bleeds ( lets air out of the radiator) you hear a hissing sound then water comes out. As soon as this happens screw back in the key
Have a towel ready as well.


More modern radiators may be a bit different but the bleed release key hole is still in same place

Sounds as if the balance has gone between radiators

Re: Heating problem ?

We bleed the radiators monthly they were done last week, we do get a lot of air in the system but I doubt that's a problem so soon. I will get the key out and do it again though if if might be that.


No the timer is set to stay on 24/7 it's very inaccessible so we use the thermostat to control the heating.

Re: Heating problem ?

You shouldn't get that amount of air in the system needing the rads to be checked that often. If you do get a plumber in get a pressure system check first that should show up any problems

Re: Heating problem ?

Do you have thermostatic rad valves to control the individual rooms or do you turn the central room stat down at night?

Re: Heating problem ?

Make sure the pump is not running by turning the stat down before you bleed them, otherwise you will get more air in there. They should be bled in sequence as well.

Re: Heating problem ?

Do you have TRVs (Thermostatic Control Valves) on the radiators? Are they all turned down lower than the one that comes on?

What system do you have Julie, do you have a combi boiler?

Re: Heating problem ?

We've always had air but it's an old system and got worse. It's serviced annually and safety checked.
No the only thermostat is in the living room.

Ah now that's interesting we have two keys so to get it done quicker I start one end of the run and my husband starts the other. Sounds like we are doing it wrong. I'll do it as you suggest see if that makes a difference.

Thanks everyone.

Re: Heating problem ?

Monthly is way too often, system has a leak and drawing in air.
Go with what Purwell said also. Turn it off and let settle for a few minutes before bleeding. The air will tend to move to the highest rad as well, unless your in a flat. Also, they won't bleed properly unless the system pressure is sufficient first.