On 11 Feb 2021 at 18:24:43 GMT, "alan_m" 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?


Water being heated too fast - turn down the gas pressure/turn down the
flame??? The fins on the heat exchanger resonating with the speed of
gas/flame passing over them???

Yes, could be. Diagnosing to that level is beyond my pay grade though :-) I'l
try to keep the thing running through the winter and get somebody in to check
calibration etc. It's had a few components changed recently - but none could
be adjusted in any way.


On my very old boiler I had a similar noise, but when the water in the
system was up to temperature. The cure was to turn down the gas to the
burners slightly - an adjustment on the gas valve. My problem only
started when the gas pipe to the boiler was changed from 15mm to 22mm so
possibly marginally increasing the gas pressure as it entered the boiler.


--
Cheers, Rob