On 8 Oct 2006 06:01:49 -0700, "Adam-the-Kiwi"
wrote:

EricP wrote:
On 8 Oct 2006 02:31:42 -0700, "Adam-the-Kiwi"
wrote:

-8- snip -8-

however, we noticed a fairly loud buzzing coming from the bathroom -
the radiator was vibrating and this appeared to be the source of the
noise. The radiator in the adjoining bedroom was also vibrating, but
much less so. The noise appears to be linked to the pump, but the
boiler itself does not appear to making any unusual noise.

-8- snip -8-

When you say "buzzing", was it a metalic hammering? Rather like an ant
tap dancing in lead clogs?

Hmmm - it's a little difficult to say, but I'd definitely describe this
as a low frequency buzz rather than a hammering.

If so, you have TRVs and they are on the wrong side of the rads.The
closing valve is vibrating as the water flows over it.

Have you had a new pump installed or turned up the flow?

No and no. The system was working fine last winter, and we've only just
turned it on for this winter.

Cheers - Adam...

Ok, go to the lockshield valve on the other end of the rad and close
it completely and then open it half a turn or until the rad works
again. Keep opening it a half turn until the noise returns and then
close it until the noise stops or reduces.