Potterton Profile 80e main burner problems

[sgrest]

I have a problem with a Potterton Profile 80e boiler. The boiler will go through sequence and ignite the main burner. The main boiler fires and stays alight for about 5 seconds and then goes out whilst the pilot remains lit. The main burner will then re-ignite and again, goes out. After three attempts, there are no more. The pilot remains alight, the fan is running, and the pump is running. To get the boiler to go through the same sequence, the mains supply needs to be turned off and on again. This is the same for both the heating and hot water although, the hot water responds almost immediately but the heating takes about 3 minutes before ignition.
The 3 way valve and pump are both working, and the engineer changed the boiler control pcb (The boiler was experiencing the same issue with the old pcb). One other thing I have noticed, is that the temperature control knob has a resistance when turned from 0 to max but then there is no resistance the other way until a few minutes later, almost as if a return spring is sticking and then freeing - I don't know if this is normal? The engineer is at a loss, and has suggested a new boiler. I'm hoping someone can help as it's been a couple of weeks now and it's a little chilly!

 

[Stuckinarut]

Maybe engage in an engineer familiar with these boilers, the fault could be anything really. A few on here know these boilers, but might not be able to advise if it refers to gas advice.

 

[JohnD]

The engineer is at a loss, and has suggested a new boiler. I'm hoping someone can help as it's been a couple of weeks now and it's a little chilly!

Find an older one. These are very sound boilers, and there are people who know them. They are not very complicated.

I suppose there might be a circulation problem, such as pump or blockage, causing the temperature to rise very fast and cut out.

 

[DP]

Your guy needs to know how boiler works before he can fix it. You have circulation issues. I strongly suspect boiler is working correctly. I would ask the “engineer” if he would not charge you any money if replacement boiler also did the same thing.

 

[sgrest]

Maybe engage in an engineer familiar with these boilers,

I have used a local company for many years but they no longer do domestic. I've spent the last couple of years trying to find someone familiar with these but to no avail.

 

[Stuckinarut]

I have used a local company for many years but they no longer do domestic. I've spent the last couple of years trying to find someone familiar with these but to no avail.

Maybe try Baxi (Potterton part of same group) fixed price repair?

 

[sgrest]

Find an older one. These are very sound boilers, and there are people who know them. They are not very complicated.

I suppose there might be a circulation problem, such as pump or blockage, causing the temperature to rise very fast and cut out.

I did have an older engineer who used to service and repair it but the company he worked for stopped doing domestic. I've never managed to find another - they're all youngsters!
I did check the header as well, this afternoon, in case it was just heating hot air. So unless the pump has lost it's impeller ....