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Andrew Smith
Andrew Smith, HVAC Technician
Category: HVAC
Satisfied Customers: 3756
Experience:  Heating and Controls engineer
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hi i have just changed the diverter valve diapham on the hot

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hi i have just changed the diverter valve diapham on the hot water & the micro switch`s to both water & c/h but the boiler will not fire up its showing flame failure . my boiler is a baxicombi instant105e

XXXXX XXXXX : If it is showing flame failure then the switches ar ok because it is trying to fire
XXXXX XXXXX : when was the lat time it was serviced and the electrodes cleaned?
JACUSTOMER-id8hjlt0- :

about 2 yrs ago

JACUSTOMER-id8hjlt0- :

but it was fireing up yesterday fine just no hot water hence new diaphram &micro switch`s

XXXXX XXXXX : When you run the hot tap, do you get a click and the boiler tried to fire?

is there any thing i can do , or is it a expert i need ,


no nothing , when i reset it takes a few second the the light comes on for flame failure

XXXXX XXXXX : It must know the tap is running or it would not attempt to start, and get flame failure
XXXXX XXXXX : i think you need someone to watch it while trying to fire and see how far it gets through the ignition sequence and take it from there

have done that , power on light on all the time .. then after a few sconds the flame failure light comes on .. no clicking or noise at all

XXXXX XXXXX : No attempt to start, could be a faulty relay on the PCB as the boiler is actually trying to light otherwise you would not get the flame failure light.
XXXXX XXXXX : are you sure the fan is not running?

yes therer is no sound of anything at all . how hard is it to fit a pcb board ,


i have got a price of £112 for a new one is that good & should i get it

XXXXX XXXXX : Just unplug all the connectors and disconnect the power, quite simple with everything off

ok going to order it , can i contact you if its not that , it may take a couple of days to get ,its bloody getting cold in the house now thanks for your help

XXXXX XXXXX : No problem just come back to me when it is done



thanks andrew pcb did the job , connectors on pcb had moved from the original but marked males with felt tip ie a2 a3 . so thanks for all your help regards bob

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