Boiler will run DHW / CH and for no apparent reason cut out, particularly annoying half way through a shower.

Sometimes shows F1 error code, sometimes doesn't.
Have to turn it on and off again at the mains switch to get it to work, occasionally leaving it 10 mins or so.

Had overheat thermistor changed, still the same.

It seems these Protherm boilers have a few common faults, although I haven't seen any specific answers to this problem - would be most grateful for any guidancel (having already spent a fortune with no luck)

Simon, July 2008

Could be a partialy blocked plate heat exchanger, DHW. Could be scale, iron sludge, installation debris, was system power flushed? treated with corrosion inhibiter? when boiler was fitted.

The Gas Man, July 2008

thanks T. Will mention it to the corgi engineer when he comes back for his 4th visit !!!
cheers
Simon

Simon743400, July 2008

firstly would be looking at the flame rectifcation device for buildup & position, and it's wire continuity.

T, July 2008