Potterton Suprima lockout, not the usual problem.

[eddyedwards]

Hi,
I have a Potterton Suprima80.
A few years agoI had the usual lockout problem. Which was fixed by replacing the PCB and the ignition wire.
The lockout problem is now back, however a new PCB and wire have not fixed it this time.
I noticed that if the white left hand external cover (the one that covers the burner) is removed it cures the problem and the boiler starts every time. Further fiddling shows that if I put the cover back on but leave a small air gap (about 5mm) by not screwing up the srews all the way, this has cured the problem too.
So, does anyone have any idea what the real fault is? Also is it safe to run the boiler like this in the mean time?
I would be very gratefull for any tips you may have.
p.s. am I wierd becouse I find boiler faults realy fascinating?

 

[stevetheplumber]

it air preasure related either air switch fan or flue

 

[md68]

It's definately not safe to run your boiler with the combustion chamber open. If I were you I would do up the screws, turn it off and call a RGI out on Monday to repair this for you. Much safer for you and your family.

 

[eddyedwards]

I stopped running it with the cover loose this morning. It is in the garage (not in the house) I hope my car hasnt suffocated. I need that for work on monday.

I was hoping that this "when the lid is off, the boiler fires up scenario" would give me a clue to the real fault ie, air pressure switch, blocked flu, etc?

The air pressure switch has 2 pipes, one goes to the fan the other is blocked with a plug. When I disconnect the one to the fan the boiler fails to ignite. So I suspect the switch is working fine (usually the boiler fires up but shuts down after 45 seconds).

 

[Village blue]

When was it last serviced? sounds like the fan may be struggling, fan speed problem.

 

[eddyedwards]

Is fixed now.
Followed vilage blue's tip. Took out the fan assmbly (realy easy).
Cleaned out some the debris inside it, oiled it and screwed it back in.
Boiler working perfect now, with the casing closed.

 

[jaynana]

Village Blue and Eddy, i seem to have the same issue, with the same boiler - help wanted pls - it's sub-zero these days!

to be precise - my boiler runs for about 1 min and stops, and then it tries again, but stops short of ignition and goes into fault-mode (red light flashing about 3 times/sec); and then in about 30 secs the cycle repeats all over again.

i opened the boiler cover, the system then works perfectly. close the cover again and the problem comes back.

I suspected the air pressure sensor and removed it and tested it - it's working fine!

does this indicate that the fan is not generating enough pressure? i realise the fan has to 'suck' for the air pressure switch to be driven and made to contact?

pls help!

J

 

[cjg]

is every body trying to kill them selfs before xmass. o lets just take the cover off this, gas +air +spark bang, o i didn"t know it was dangerous!!!!!

boilers can and will kill, carbon monoxide, air leak, gas leak, BANG,

christmas cancelled for some one...........................................................

 

[bobbybulls]

having same issue too. PCB has been replaced this morning. all was looking good, boiler fired up and ran for about 25 mins, has then locked out again. Now awaiting Air Pressure Switch to be replaced.
Will advise if this does the trick

 

[Pancho]

Hi, did this ever solve the problem?

 

[Dotty]

Shifting to private forum too much info for the public forum.