My boiler keeps getting the red fault light on permanently. The boiler lights OK but then shuts down after about 2 secs. This occurs 5 times before the ignition lockout occurs. The yellow flame on light never illuminates.
The following parts have been swapped with my freindly neighbours boiler without success:
Ignition PCB, Control PCB, Interface PCB, Fan, Burner Box front cover which includes the ignitor and the flame sensor.
We've checked that the Condesate trap is clean and clear. Confirmed that the wiring between the Ignition PCB and the flame sensor is ok. Checked the Gas Valve sense tube to the burner box is clear. The transformer is ok.
Does anyone have any other ideas before I call Heat Team?
this is a common problem if after replacing the seals the heat from the burner burns the seals off again the problem is the back of the heat exchanger is blocked.......new heat exchanger ......may as well buy a new boiler.
gibbo
February 2012
Definately the combustion chamber seal needs renewing as the existing seals corrode easily so the fan overheat stat keeps locking the boiler out on overheat.
James
February 2011
Try the combustion chamber seal. my boiler suffered similar symptoms and I found part of the seal burned in the bottom corner. Replaced seal, all sweet again!
Quirky Steve
November 2010
try replacing wiring harness £46ish includes electrodes wiring to all sensors and gas valve and ignition lead.had a lot of trouble with this type of boiler that sequence of lights could be pcb,waste problem, wiring harness,or a number of faults check the burner and the seal around the inner case were the burner is housed
lee
January 2010
The only way I found to fix this problem,plus what you have already done,was to increase the pump speed to middle setting.
maxwell
August 2009
I was thinking along the same lines because that's about the only part I haven't replaced yet, but the valve does open because boiler lights initially then shuts down. I followed the fault finding chart in the manual to the point where it asked "Is there 230V ignition PCB burner on pin to control PCB" this is the red wire between the Ignition and Control PCB's. The answer is that there is not 230v, the max it ever reaches is about 3v when the boiler lights. The fault finding under these conditions says replace the Ignition PCB which I've done and it still fails to stay lit.
Ian C
November 2008
I was thinking along the same lines because that's about the only part I haven't replaced yet, but the valve does open because boiler lights initially then shuts down. I followed the fault finding chart in the manual to the point where it asked "Is there 230V ignition PCB burner on pin to control PCB" this is the red wire between the Ignition and Control PCB's. The answer is that there is not 230v, the max it ever reaches is about 3v when the boiler lights. The fault finding under these conditions says replace the Ignition PCB which I've done and it still fails to stay lit.
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