Central heating pipes 'banging/knocking'

[callum84]

Hi,

I have recently moved into a property and the central heating was working fine (quietly), then suddenly a couple of days ago, when I put it on, and when it goes off, there are banging/knocking noises coming from I think the hall/spare bedroom (hard to tell exactly)

Its an Alpha combi boiler with radiators/heated towel rails.

I have tried 'swatting up' online, ie to find solutions/causes, expansion/contraction/air in system etc, although I am still seeking some advice or potential causes?

We have just moved into the property (3 weeks ago) and I know probably the best thing to do would be to call a plumber/C.H engineer, but to be honest finances are abit tight and I am hoping it will not be a big issue to repair?

The other problem is that the floor finishes are all sealed so to speak with new carpets, tiled floors etc and the crawl space in the sub floor is only about 400mm, so I am hoping there could be a solution without having to lift a floor finish?

Really stressing as it is at the point of not having the heating on when sleeping or in early morning before work as the 'thumps' are so loud. THe other worry is that these noises could be causing damage to the CH system?

I would REALLY appreciate some thought/guidance?

Regards,

Callum

 

[mysteryman]

If the banging is rhythmical and only starts when the CH has been on for a while, it is probably a thermostatic radiator valve [TRV] with the heating water flowing in the wrong direction. Try turning the valve up or down when it is banging; if the banging ceases, that is the problem. Some makes of valves can be adjusted for correct flow direction without draining down. Tell us what make it is.

If it is random banging, it may be that there is no circulation through the boiler, which is then boiling. Don't let that happen, and call a serviceman immediately.

 

[callum84]

The banging isnt coming from the boiler (boiler was installed new Jan 2011 with 5 year guarantee) it seems to be from the C.H pipework in the hall and to the spare bedroom.

It seems to be a couple louder thuds, then more of a rhythmic sequence of bangs until it eventually stops the later happens when the heating goes off, and then just the odd light bang/ping sound there after until nothing. I was thinking could be a expanding/contracting issue, but then thinking why would it just have suddenly happened?

We have just bought the property (approx 4 weeks) and there has been no issue until now, ie the banging noise, I only really just noticed it a couple of mornings ago when the heating went on at 5am.