On 11/02/2021 17:52, RJH wrote:
On 11 Feb 2021 at 17:21:13 GMT, "
wrote:

On 11/02/2021 15:50, 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. Once it settles
down after 5 minutes or so the noise more or less goes, maybe fades in/out
for
a few seconds every so often. Recording clips at:



https://drive.google.com/drive/folde...2u?usp=sharing

(After 5 minutes - noise more or less gone, normal sound)
(First 5 minutes - new noise, boiler from cold, stops after about 5 minutes)

Internet searches tend to suggest gas valve, although this sound can't be
heard outside, and the reports I've read suggest it doesn't stop after a few
minutes. Replacement looks relatively straightforward - 5 minute job. Any
comments please?

If it's yours, and you consider yourself competent, removing the cover
should help you track-down the source. If you're asking out of interest
and will get someone else to fix it then an image search for "ideal
logic boiler parts diagram" should give you an idea of the probable cause.

Thanks - I've got a decent manual, and I'm quite familiar with the workings.
Just I'm having trouble diagnosing this problem. That said, you're right - I
could almost certainly diagnose it more accurately with the cover off, but I'm
not sure about doing that with the boiler running.

With most conventional modern boilers no combustion gases will flow into
the boiler casing and so safe to run with the casing off.

I would be tempted to shut off a couple of rads during the first 5 mins
and check if there is a change in volume or tone.

With the cover off I expect you'll be able to detect the issue by
feeling the vibration from the offending component. Pump / fan / gas
valve. I have known heat exchangers amplify noise by hitting a harmonic.