'banging' central heating

[horribleman]

I've read the FAQs on this, and spoken to family members that are in the trade, but I have so far failed to solve the problem.

I have a little Baxi boiler that provides both the central heating and hot water.

Sometimes when I turn the heating on it starts thumping around the pump area. The boiler is downstairs and the pump is upstairs in the airing cupboard.

I've tried bleeding the rads, and there always seems to be air in them.

There seems to be a couple of 'spout'-like things on the pump with square nuts - are these to let air out of the pump?

I realise I probably need to eventually get a one of those de-aerator things, but I can't afford to spend anything at the minute.

What's my best course of action in the meantime? Sometimes it bangs for a bit then settles, sometimes it's fine. It just seems a bit random.



I've just bought my first house and so I'm skint

 

[kevplumb]

There seems to be a couple of 'spout'-like things on the pump with square nuts - are these to let air out of the pump?

no they are the isolation valves

pump is bled by undoing the centre screw

 

[horribleman]

Cheers, I was about to try those isolators last night. Glad I asked here first.

I'll try bleeding the pump, and I have also read that it might pay to turn it down.

I suppose a trip into the loft is in order also to check the expansion tank is not dried out etc.

Thanks for the advice.

 

[sandwell]

Have you checked that the header tank has not run dry. A common cause of this kind of problem.