Hope someone can help. My Worcester rd532i condensing boiler was working perfectly fine for year, then 1 day there was no power so had the pcb board replaced by a gas safety engineer.

It worked fine till the next day when it started showing FA fault. Kept resetting the boiler and it would then work. Spoke to the engineer who said he doesn't know so will need to come and check it but would charge per hour. I kept resetting & emptied the bottom of the siphon out which eventually resolved the issue. It worked well for a while but then started showing error code f7. The boiler cover was removed and cleaned but had the same error code.

Today after resetting it worked fine all day and then FA error showed in the evening. Each time I reset it it alternates between error code FA & F7 so one time it's error FA then another time it's F7.

The engineer ain't got s clue & this is driving me MAD! The electrode has been cleaned, do you think it needs replacing?

Many thanks in advance!

Hunter_, December 2015

F7 = FLAME DETECTED ALTHOUGH APPLIANCE IS SWITCHED OFF Check electrode assembly, dry pcb. Flue clear?

FA = FLAME DETECTED AFTER GAS SHUT OFF
Check gas valve and wiring to gas valve. Clean condensation trap and check electrode assembly. Flue clear?

If your gas safe registered engineer hasn't got clue then get yourself a different engineer - you pay them for their expertise in diagnosis and repair - it's called professionalism.

F7 and FA appear to be the same fault - flame detected - clearly there will be no flame because your boiler does not ignite - so the flame detection is a false message.

There will be a flame detector electrode (which you have cleaned) that communicates to the control board - the fault condition happened immediately after the pcb was changed so it's easy to assume that work somehow caused the faults you see - either the new pcb is faulty or an electrical connection to it is bad or the flame detection electrode is giving a false signal.

I have several clues and I have no experience with boilers.

Good Luck..., December 2015

Some interesting stuff here (May be worth oosting on this forums as it's specialist:

http://www.diynot.com/diy/threads/problem-with-combi-boiler-bg-worcester-bosch-rd532i.193778/

and

http://www.ultimatehandyman.co.uk/BOSCH%20_WORCESTER_CONDENSING_BOILER_FAULT_CODES.htm

XXX, December 2015