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

Hi All,

We've just turned our heating system back on for the winter - boiler is
a Baxi Combi 133HE Plus. All the radiators seem to be heating up as
expected and, as yet, none appear to need bleeding. This morning,
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.

Can anyone give me any suggestions as to the cause?

Cheers - Adam Cheney

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

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?