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Michael Shergold Michael Shergold is offline
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Default Problem with Potterton Promax 15 HE boiler. Ignition lockout

"Michael Shergold" wrote in message
...
Boiler now seems to lock out but only after is has reached it operating
set-point. That is it doesn't lock out if either of the thermostats
(cylinder and room) switch it off first.
The CORGI registered installer/maintainer (it's four years old) has now
replaced the igniter and sensor and both the main control PCB and the
Ignition PCB have been swapped out and so we are pretty sure it is none
of those. I'm wondering if the safety cut-out is operating before the
setpoint is reached.. Perhaps we should start measuring the
temperatures. I guess by closing down all the TRVs we could speed the
process up a bit. He's loath to hang around all day.
Or could the control thermister not be functioning in and allowing the
boiler to overheat. It's currently set to operate at the factory set
point of 82 degrees. If anyone else has had this problem with this
boiler I'd like to hear their solution or suggestions..
Michael


Follow-up: In case anyone has similar problems

A second person was also experiencing exactly the same symptoms and over
a week ago we conducted various tests and experiments measuring maximum
temperatures and checking thermister values etc.. This duplication
encouraged my Corgi man to phone Pottertons and at their suggestion on
Nov5th evening he came and inspected the combustion chamber door seal
and found it to be leaking.
Coincidentally the other person had also decided to take off his combustion
chamber door and found that there were large gaps in the sealing strip.
Both Boilers have now been re-sealed and are back in test mode.
It is all looking promising as we have at last found something
promising. Curiously my Promax locked out again twice during next two
days day but not after a long heating spells as before. It has now remained
lockout free for the last week now, so the jury must still be out on
whether we have eventually determined the ultimate fix to this boiler.

There are still significant questions though:
How did both CORGI engineers miss this during the annual service or at the
very least not investigate this when called back to investigate the
problem?. (no doubt the seals was damaged before or during the service.
Both boilers had been working faultlessly until the annual service. )
The Potterton service manual supplied with this boiler is pretty poor,
(decision blocks with no real decision)! The combustion chamber seals
come low down the list after changing almost everything else.
Do boiler manufacturers like Potterton not have any further contact with
installer/maintainers or customers?
The spares supplier said that these door seals were often ordered!
I've written 'Check firebox door seals' in large letters for the engineer
next time.
Michael