Question about getting air out of CH boiler please

[sololite]

Hello

Our British Gas 330 condensing boiler in an open vented system sounds like it has air in it and I want to bleed it out.

There is a drain valve in the pipework above the boiler and I attached a hose and opened the valve. Nothing came out, neither air or water.

The YouTube vid I was copying said everything should be switched off when bleeding the air. Is this the correct procedure? I seem to remember when I bled it years ago following a new radiator that I had the boiler running when I bled it.

Nb . I've aleady bled the radiators and magnetic cartridge

Nb. The hot water circuit has been running for months without clanking from the boiler but started yesterday after we had run the CH for several hours.

Thanks for advice!

Chris

 

[terryplumb]

The drain cock is probably stuck closed by its internal washer. If it's above the boiler it's not likely to get any air out that's trapped in the boiler.
Is the boiler functioning ,heating radiators ok ?

 

[sololite]

Thanks for taking an interest Terry. I've attached a pic of the drain valve location. Yeh rads and HW are fine. Boiler isn't locking out , just knocking

 

[fixitflav]

Thanks for taking an interest Terry. I've attached a pic of the drain valve location. Yeh rads and HW are fine. Boiler isn't locking out , just knocking

Are you sure the F/E tank is full? The ball valve can stick closed.

 

[sololite]

Yes it's full and ball cock seems to be operating. Tank is clear water but nasty orange sediment in it. I haven't put any anti corrosion in for a few years (yeh I know) could there be crap in the system? Boiler was serviced in summer and engineer said she was running fine for something of that age. Other than drain down the whole thing and put anti corrosion in, I can't think of anythig else to try other than call an engineer

 

[terryplumb]

If all is working ,but boiler making a clanking noise ,then I would suggest you call an engineer in.

 

[sololite]

If all is working ,but boiler making a clanking noise ,then I would suggest you call an engineer in.

Thanks Terry , it was air in the system. Its only when you call your insurer that you find out the boiler cover you are paying for is as useful as a chocolate tea pot. So I drained down and refilled carefully after a spell of X400 etc. and clanking disappeared. I think initial problem was with header tank and sticking ball valve but will never know for sure. Thanks for your advice