boiler flame problem

[ljgarrett]

workng on a gloworm 24ci boiler,flame comes on when running but quickly goes out ,then keeps lighting again for a few secounds ,then out again.keeps repeating this over and over.so heres the question,could it be the flame detection module on the pcb or the flame sense electrode or ?.please help as this boiler in a pain in the ar**.thanks

 

[Puddle]

No If it was flame retification it would go to lock out,first check for a flue problem,check out side,then air pressure switch

 

[Billy Bob Bob]

do a continuity test on the detection electrode,as puddle says could be a air switch but if this is a band a it may not have one also test primary [ch] thermistor please say if its a band a condenser or other wise to get a better feel of the boiler

 

[ljgarrett]

the boiler is a modulating non condensing boiler.thnks

 

[Billy Bob Bob]

with what puddle says but check gas pressures , thermistor flue and ap switch does it run normal with combustion door off?if so venturies ,air tubes ap switch[likely] or flue blockage good luck post back with results

 

[ljgarrett]

does the same with the combustion chamder door off