Although the boiler is firing up , after about 10 minutes of heating it seems to stop, start stop start quickley , the flame never goes out , nor the fan stop , but obviously its not right , when this happens , on the pcb LED 4 flashes off and on ,, it has not cut out and still heats the water etc , but the noise is a pain, Usually its the fan that causes me trouble , ive just re-lubed the bearings and cleaned it up and that sounds alot better , cleaned the ignition , its had a new pcb , fan , and right hand solonoid in the last year , as its intermitten I cant really see if its the pressure switch or not , any clues?

Jason Spencer, May 2012

no , i did checked the pipes for leaks , but the problem stopped now , and seems to be working fine ... thanks for your help

Jason spencer, May 2012

when you replaced the fan did you also replace the silicone pipes connected between fan & APS?

manwithnoname, May 2012

Ive changed the Electrode and its still doing it , could it be the fan is worn and not up to full speed ?, although it doesnt appear to slow down ,, or the pressure switch ?

Jason spencer, May 2012

thanks , I was thinking that , seems to simple though , but as thats the only part never to of been changed il give it a whirl , thanks

Jason spencer, May 2012

glowworm ultimate 55ff
41-047-55
burner cycles on & off
LED 4 lit
ignition pilot or flame detection fault
sounds like a classic case of detection electrode shorting to earth
spark/detection electrode 202626 £23

manwithnoname, May 2012