Back boiler vibration

by **Spinner** » Fri Feb 01, 2008 6:54 pm

Hello there! Anyone got any ideas how to cure my central heating noise? Turn it on in the morning and it's fine for the first ten minutes. Then a vibration from the system starts to cause the expansion pipe to knock. After about half an hour the noise gradually reduces but doesn't completely disappear.
I thought it could be kettling, but as the noise reduces rather than gets worse and I've put some additive in to cure the kettling effect, then I think not.

Any guidance would be greatly appreciated

Thanks

Spinner

by **htg engineer** » Sun Feb 03, 2008 6:01 pm

It does sound like it could be kettling, depending on how bad the build up of limescale is - the descalers very rarely solve the problem.

Whats' the boiler make and model ?

by **roger196** » Sun Feb 03, 2008 7:24 pm

Sounds like heat expansion of the pipes. Check that pipes are clipped at regular intervals. Look for a pipe that is vibrating, does noise disappear when you hold it, whcih may need an extra clip.

by **Spinner** » Sun Feb 03, 2008 8:12 pm

Thanks for the replies,

Yes I can reduce the noise if I wedge some carboard between the wall in the airing cupboard and the expansion pipe. Or pull the pipe to one side very hard, but the noise doesn't completely disappear and you can feel the pipe wanting to vibrate. If it was just a case of resecuring the pipe work then, just holding it would make the noise go. But surely thats just trying to stop the noise, rather than curing the fault thats causing the vibration, isn't it?

The Make of the boiler is a Potterton 45 or 55.

Thanks

Spinner