Banging radiators

[Guy Snape]

For the last month or so our radiators have started to make a banging noise as soon as the central heating comes on, continuing for about 20 minutes (?) until the radiators are hot. A plumber came and had a listen, bled the radiators, then decided it was probably due to gunk in the system and we should have a power flush, which would cost four hundred quid. Given that he said "probably", I'm inclined to get a second opinion from another heating engineer. Can anyone here offer any advice?

Thanks in advance,

- guy

[R]

Could need a proper descale.....Raden will be along in a minute to sort that out... ;-)

[RzB]

"Guy Snape" wrote

Hire a power flushing machine and do it yourself - it's not difficult if you are able to remove/fit the pump.

Our local plumbing shop charges £47 / day.

Roy

[Ed Sirett]

The banging might be coming from kettling or from a loose and/or reversed TRV.

Most banging seems to get worse as the water heat up. Given that it has come on suddenly the pump would be in the frame.

[Guy Snape]

Having never done that before, I'm not sure - can you point me to some reliable instructions online somewhere?

Thanks,

- guy

[fred]

In article , Guy Snape writes

Do you have a closed/pressurised system (with a pressure gauge) and if so does the needle oscillate in time with the banging?

After the above, open the TRVs fully and see if this or stops the banging, either on a rad by rad or on the system as a whole.

[Martin Pentreath]

They don't get much more detailed than this ...

[Guy Snape]

TRV = Thermostatic radiator valve? We have those on all the rads, is there anything I can look for specifically?

Ours definitely stops when the radiators are hot.

Again, is there any sort of diagnosis I can do myself?

Thanks,

- guy

[Guy Snape]

No. I think it's a pretty old system - we bought the house ten years ago, and I don't think it was very new then. We've got a Baxi Bermuda back boiler behind the gas fire and a hot water cylinder in the airing cupboard upstairs. No gauges of any description anywhere.

and if

I think we had all the valves fully open when the weather was cold a few weeks back and it didn't make any difference.

Thanks for the help,

- guy