Radiators not bleeding properly Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[jamiebogle]

I had a new central heating system installed a couple of years ago, and have occassionally had to bleed the odd radiator. However 3 radiators in the house don't bleed at all. When I turn the bleed valve there is no rushing off air coming out so the rads never get any better than luke warm.

Two of the rads are close to the boiler, one is downstairs.

Any help out there?

[Steve the gas]

Hi,

Only bleed rads with the system OFF.

[jamiebogle]

That still hasn't worked. It's almost as though there is no pressure forcing the air out of the affected rads.

The pressure bar on the combi is what it should be however.

Any more ideas?

[htg engineer]

As StG says, plus what kind of system is it ?

I'd imagine it will be pressurised with it only being a couple of years old. So what is the pressure gauge reading ?

htg

[jamiebogle]

The boiler is a Worcester Greenstar 28i junior.

The pressure gauge reading is showing about 1 1/2 and the guide marker is 1, so there's slightly too much pressure in the system at the minute, but it always fluctuates anyway between 1 and 2 when the boiler is on, which I guess is to be expected.

[htg engineer]

1.5 bar pressure is fine, very odd for a pressurised system not to refill easily.

Did you try venting the rads with the CH turned off ?

The vent may be blocked, turn off both rad valves, remove vent nipple and insert a pin into the rad vent point.

(this is in relation to other posts - this is a common fault especially if leak sealer has been added at some point, that's why i'd only use leak sealer as a last resort. Also causes problems with auto airvents)


htg