Air surging noises

This was emailed to me, thought it better to put it here:

The original post I left was Surging noise when CH runs!

I was wondering if you could advise me further regarding this ongoing problem of mine? Your last thread advised me that the water level in the F&E tank should only be about 100-150mm deep and mine is currently about, say double'ish that. But not so that I would have thought it would cause a problem. The situation is though, that I'm still getting a rushing of air/water sound through the pipes which sounds intially like its coming up through the boiler (bubbling noise) and then I can hear it coming up though the pump in the airing cuboard. This happens about every 20-30 secs through a cycle. I recently opened up the auto air vent next to the storage tank in the airing cuboard which was initally leaking water to which now it doesn't, but was thinking that this may be where the problem actually is. Is there some sort of test I can do to eliminate the auto air vent? Or maybe it just needs changing.

Any further adivise will be appreciated.

Might be best to replace the auto air vent with a manual one just to eliminate it. More reliable long term too.

Have you checked if the vent sucks air - were you the half a tumblerfull one??

You could try smearing Fernox LS-X over the connections on the inlet side of the pump, or putting Internal Leak Sealer in the system.

Cheers ChrisR

Yes mate I was the half tumblerfull one. Still having same old problem.

Obviously a bit reluctant to change auto air vent if it means draining system again.

But it seems this may be the only course of action to take to maybe sort this problem out. When I fitted the new pump in the first place I did use a jointing compound around the old olives on compression joints and there doesn't seem to be any sign of a leak from the pump itself. Although I guess it wouldn't take much of a drag from the inlet to bring air into the system. Or should it be obvious if a leak is present.

Do you think that applying a brush and say fairy liquid around the valves on the pump whilst running will show me any sign of air being pulled in?

That occured to me too - but I don't know !
Re the AAV, if you put a ring of putty round the top to make a pool then put water in it...

Also many aav's are designed to be removed without draining the system, having a seal at the bottom...

Perhaps its time for a scruff drawing