On 11 Feb 2021 at 16:50:13 GMT, "Tim+" wrote:

RJH wrote:
After 3 component failures in the past few months (heat engine, water
pressure
sensor, pressure gauge), it's looking like my Ideal Logic + is on to its
4th.

On starting heat or water and for about 5 minutes, the boiler makes a loud
resonating sound, a bit like a bearing on its very last throes. It's
difficult
to tell where it's coming from with the cover on, centre up. I don't think
it's the fan - the noise stops once the boiler stops firing.

Surely thats when the fan stops too?

I think the fan carries on for a short while after the burner switches off.
The noise certainly sounds like more than I'd expect from just the pump.


My money would be on the fan motor bearing. Having said that, we once had
a boiler that howled due to kettling. This was down to a low static head
of pressure and a pump that wasnt removing heat fast enough.

Yes, thanks, could be. This is a sealed system and the pressure's fine, but I
did post a while back about the burner switching off and the pump running
during heating. So maybe there's a bit of runaway and a failed sensor
somewhere. It's certainly not the sort of sound I'd expect a valve to make.

--
Cheers, Rob