Cold radiator - been bled

[rinkydink1973]

Hi

I have just bled the radiators in my house as two of them have been bubbling and doing the warm at the bottom cold at the top thing for a few days. All the radiators are working fine except for the one in the dining kitchen which is stone cold.

I'm not sure if it is the first or last one in the cycle as it was newly fitted 3 years ago (we have had no problems till now). It has 2 panels.

There are two pipes - one going in and one going out and they come down from the ceiling. At the ceiling, the incoming pipe is hot, the outgoing pipe cold. Then the pipes are boxed in (this was only done a couple of weeks ago) and at the bottom, both pipes are stone cold.

Is it possible that there is air in the pipe preventing the hot water from coming down? Should I bleed the radiator for longer? I have bled both panels until water comes out. Or is it possible to bleed the valve?

Any help gratefully received!!

 

[Softus]

You might have a blockage, but approach it the easy way first.

Shut off one valve at all radiators except one of the troublesome ones.
Turn the heating off.
Vent air from the troublesome rad until water emerges.
Turn on the heating - ensure that both valves are fully open on this rad.
See what happens.

If this works, repeat for any other rad that isn't getting fully hot.

If not, do you have TRVs?

 

[rinkydink1973]

Ok am going to sound completely stupid but what exactly are TRV's? Is it something like temperature regulating valves? If so we have those.

I have already bled the radiator until water came out - both panels. SHould I do this again as per your instructions? If water does come out stright away, should I keep bleeding it for a period of time. Is the system likely to run out of water??!!

 

[rinkydink1973]

Your suggestion seems to have worked, altho' I do think there is an air bubble going around the system. Unfortunately, the one radiator that I haven't been able to bleed because of size issues (the key, not me!! ) is the one that I think is causing the problem. It's never been particularly good, but hubby is back tomorrow so he can sort it then!!

Once again, many thanks, now I have a warm kitchen!!

Rinkydink

 

[Softus]

There are no stupid questions - you don't know what you don't know.

TRV = Thermostatic Radiator Valve

The TRV on the cold radiator might be stuck shut, or partially shut.

You can't run out of water, but if you have a pressurised system then you might reduce the pressure.

Do you have a combi boiler? Or any other kind of unvented heating system?
_________

Note that having to vent regularly is a symptom of an underlying problem with your system. It's possible for an installation to draw in air, either because of a blockage or because of wrong pipework.

It's also possible that the gas in your radiators is not air, but Hydrogen, which is generated if the radiators are corroding.