Banging Noise Glowworm boiler

[studillon]

Hi - I'm new to this website and I know absolutely nothing about Plumbing or Central Heating.

I have a Glowworm Ultracom24cxi boiler - situated inside a specially built box on the wall of my kitchen. Every now and then I hear a loud clanking noise coming from the box. I'm absolutely certain that it is coming from the boiler and not from the pipework that is also housed in there.

It happens sometime during the day and sometimes at night. It doesn't seem to matter whether the boiler is heating the radiators or not (ie it still happens when the thermostat is set so low that the boiler is not operating).

I've just had the boiler serviced and it's in good working condition. My Service guy can't shed any light on the problem as when he was there the noise didn't happen.

Can anyone give me any clue as to what might be causing this....

 

[lame plumber]

are you turning off taps or washing machine etc working when this happens, if so loose pipe work and water hammer

 

[studillon]

Thanks.

No - frequently the noise happens when no taps or water has been flowing anywhere in my flat for several hours.

 

[studillon]

Thanks for your suggestion - but frequently when I hear the noise none of the taps in my flat have been on for several hours...