Potterton Performa 28 Fan Hunting

[hungryhippo]

I have a 18m old Potterton Performa 28 combi and all last week it was intermittently needing to be reset.

On one morning the boiler didnt light up at all until reset, then it ran OK for hours. On another occasion the boiler lit on the timer and ran for hours then went into reset and on other occasions it was fine. I replaced both spark and flame sensing electrodes and it ran ok for 2 hrs. Then last night it needed re-setting but this time the fan was hunting - starting and stopping, second by second. The pump is running OK, there is gas and electric and the flue is clear. Early on in the week the boiler reset no problem but last night with the fan issue it took 5 mins to reset it.

If I turn it to dhw only the fan hunts as when on dch mode. Can anyone shed any light on this please. Do I need a new pcb?? Thanks

 

[fitz1]

is power fluctuating at the fan

 

[hungryhippo]

is power fluctuating at the fan

Dont worry, I'm not touching anything gas-wise. Power is steady at the fan. It's an intermittent fault when sometimes everything seems fine, then another time it wont light due to the fan hunting. Is it worth changing the air pressure switch?

 

[Agile]

Dont worry, I'm not touching anything gas-wise.

But you already have! The gas ignition electrodes and the flame sensing electrode are part of the safety circuits.

The fan is inside the combustion chamber which is also part of the gas train.

Tony

 

[ChrisR]

It's a standard problem, you need a new ***********.

 

[hungryhippo]

Dont worry, I'm not touching anything gas-wise.

But you already have! The gas ignition electrodes and the flame sensing electrode are part of the safety circuits.

The fan is inside the combustion chamber which is also part of the gas train.

Tony

Fair point, but I cant get a gas engineer for another week and the wife and strife are on my case. Have you ever changed a wheel on your car? Are you a trained motor mechanic?

 

[hungryhippo]

It's a standard problem, you need a new ***********.

Thanks for that.