Potterton 80 Boiler

[Geoffitaylor]

I have a Potterton 80 Fanned boiler. When the control unit calls fo

boiler operation the usual process is as follows:

Fan starts up

Ignitor lights pilot

Pilot lights Burner

Fan keeps going

Heats water

My boiler has now started playing up as follows:

Fan starts up runs for a few seconds

Fan switches off

Tries again

Switches off

Tries again

Ignitor lights pilot

Pilot lights Burner

Fan keeps going

Heats water

The fault is intermittent and usually takes a few times to light th burner but can sometimes go through the correct cycle first time. Whe it plays up the ingnitor doesn?t seem to be trying to light; i actually doesn?t seem to get to that stage. It is though something i stopping the cycle before it is ready to ignite.

Any suggestions please?

Geof

-- Geoffitaylor

[Roger]

The message from Geoffitaylor contains these words:

When that happened to my Potterton (Profile Prima) it turned out that the fan bearings were drying out and the fan turning too slowly to operate the pressure switch. I bought a new fan at an outrageous price only to learn long after the event that Geoff (Raden) does reconditioned units.

[Ed Sirett]

This is probably a Profile. This is a classic failure mode for the PCB module. It sound as if yours is not quite dead yet, but probably will be for Christmas eve.

About £50 will get you a reconditioned unit raden will tell you more.

If this is not a Profile then it's the same sort of fault on another model but a significant proportion of Profiles fail in this way.

[Tim Lamb]

I think I have just joined a club...

Potterton, definitely Profile, 10 years in work finally died this evening.

Service carried out a week or so back and the engineer left muttering about brittle pipes to pressure switches and possibly dying PCB.

The only symptom I was vaguely aware of was the ignition sparking long after the pilot was lit and the fan occasionally running with no flame in windy weather.

OK chaps. What is the best source of spares from central Herts.? And what am I likely to need?

regards

[Ed Sirett]

You have a profile (a very diagnose-able and repairable bit of kit). However you have very different symptoms to the OP.

The pilot on but no main burner is down to only a few things.

1) Flame detection failure. i.e loose wire to electrode. Bad PCB. 2) Contacts, joints and cables especially the connector to the PCB and gas valve. 3) A bad gas valve (unlikely especially as you get a result from time to time).

An apparently dead Profile:

Assuming the permanent and switched input are on. Assuming the thermostat is up. Then the most likely thing is

1) The over heat has tripped (this requires a manual reset by pushing the brown button in under the casing. 2) The fan is totally dead (or it's wiring is faulty).

[Tim Lamb]

Yes.

Yes

Done that. Not tripped.

Fan now running after pcb repair.

As you say, it is not a complex piece of kit. I suppose disconnecting the pressure switch to access the pcb may have triggered a second fault but the pipes and connections look visually sound.

I'll try again in the morning. Most of this evening has gone on producing a print file for the family Christmas card.

regards

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