On Sun, 31 Aug 2008 14:23:45 +0100, "John"
wrote:

A friend (as in the Flue question) has had a combi fitted upstairs (new flue
through roof). The fitter did a great job, but the electrician needs to come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control. However, what is the noise - is it a fan?

It could be the pump. As the thermostatic valves on the radiators
close, the pump faces increased resistance (or something). It will
start off quiet and get louder as the house heats up if this is the
case.

The thermostat circuit could be low voltage in which case you could do
it yourself