I think that it is not the boiler itself, but the honeywell control
unit that runs the programme. Should I get this replaced as well?
Kevin.
> Hi all, I've read the messages from 2006 and before regarding
> potterton boilers. I have a Suprima 50L which is "locking
> out" (showing as a red LED).
Do you mean that the red LED flashes twice a second whilst the green LED
is off?
> The boiler tries to fire up, initiates,
> lights, runs for about 15 seconds and then locks out again. Now the
> reason for posting is that the engineers have been out twice and
> replaced the circuit board within the boiler and the air pressure
> switch. They run a quick test, i.e. turn it off and then turn it back
> on again, and the boiler always fires up. The infuriating thing is
> that as soon as they have gone, the boiler locks out again (after
> about an hour). This has been ongoing for about 2 weeks now and is
> costing a fortune in repairs.
I assume you mean they replaced the OCB on one occasion and the APS on
another (rather than replacing the PCB twice)?
> I think that it is not the boiler itself, but the honeywell control
> unit that runs the programme. Should I get this replaced as well?
Why do you think that is to blame: how could it cause the observed problem?
--
John Stumbles
Things don't like being anthropomorphised.
> I assume you mean they replaced the OCB on one occasion and the APS on
> another (rather than replacing the PCB twice)?
Oops I mean PCB. To replace it on the first occasion is reasonable for
this boiler. If they replaced it with a Potty one rather than one of
Geoff/CET's recons there is a possibility that the new one is also faulty.
In any case I wouldn't suspect the APS (but maybe I haven't RTFMed hard
enough) and I certainly would want to do more than "a quick test" (how
quick?) to satisfy myself that the system's working properly.
The manual's fault-finding section seems to be a chocolate teapot on
this: it only deals with what the boiler does from switch-on, not what may
occur after a while. I'd be thinking what could cause a genuine lockout,
maybe ignition problem or gas supply or gas valve problem.
--
John Stumbles
Men are from Mars, Women are from Venus
and Pop Psychologists are from Uranus
please don't call them engineers
Did they leave the original HT lead and is it red ?
It sounds like it's not flame sensing properly. If the pcb has been
replaced, then the next thing to suspect is the HT lead which is used by
the pcb to sense that the flame is alight
NOTE TO JOHN, ED et al.
Any time you come up against a Suprima with a red HT lead, it's a common
reason for flame sense failure -it's carbon fibre, not wire and
shouldn't be trusted
--
geoff
> Any time you come up against a Suprima with a red HT lead, it's a common
> reason for flame sense failure -it's carbon fibre, not wire and
> shouldn't be trusted
Thanks Geoff - noted
--
John Stumbles
I've got nothing against racists - I just wouldn't want my daughter to marry one
Thanks.
I would have probably thought this is a flame sense problem if the boiler
goes for only 15 seconds, but I would have missed the HT lead problem.
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Ah - that's one instance where the Suprima is fairly specific and
consistent (although I have come across exceptions)
It will spark 13 times then shut off the GV and fan
it then sequences through again twice more
it then goes into lockout
--
geoff
> Any time you come up against a Suprima with a red HT lead, it's a common
> reason for flame sense failure -it's carbon fibre, not wire and shouldn't
> be trusted
Maxie, what are you actually saying? Replace the lead type for type, or one
which is copper? Is a copper lead available ? You appear to indicate so by
mentioned some leads are "red".
replace the red carbon fibre lead with a wire one
Potterton are also replacing them as quickly and quietly as they can
The new modules come with a metal HT lead
--
geoff
This sounds like the problem that I am having. The boiler initiates
(fan whirring) then I hear the boiler ignite and see flame through the
window, it continues to burn for short time and then stops. The LED
then flashes red. However this is so random, for example, it sometimes
starts as timed in the morning and runs the programme, then in the
evening it will not start, cycling through the lockout, ignite,
lockout process.
Kevin.
Thanks for the enlightening discussion of my problem. I'm about to
call out the engineers again today and I'll discuss what you have said
with them when they turn up.
Thanks again.
Kevin.
--
geoff