baxi combi 80e pcb (am i being ripped off?)

[tommyr]

a few months ago my boiler developed a fault where the ch didnt work (pump led flashing) but dhw was still working fine. i decided it was the pcb so i got the gas man in who agreed and changed it. it all worked fine until last week when the boiler stopped working (no spark). i decided it was the pcb again so i got him back and he put in another one. it worked all weekend but has now gone wrong again, this time saying it is a fan problem.
i asked the guy on friday about stuff i have seen in various forums about the board being dodgy and needing to be upgraded. he says that is true but on top of the cost of a new board he wants 300 quid for the conversion process and i am suspicious of this because all the references i have seen indicate it is just a straight swap.
my 3 questions therefore are

1 does this conversion process exist or is he trying to fleece me?

2 is there any way something in the boiler could be causing these problems or am i being sold dodgy boards?

3 can anyone clarify accuratley that i do actually need an expert to do pcb changes or can i do it myself? (i have heard conflicting opinions on this issue)

many thanks for any advice.

 

[namsag]

there is no conversion basically it is a redesigned board which has been out for at least 3 years now ,board costs around 85 inc.And should be the one coming off the shelf.
You may well have a couple of faults on boiler. Fan flashing usually indicates faulty air pressure switch. one of the most obscure faults you will get on these is the multi pin plug to gas valve breaks down inside . And boiler goes to flame failure intermitently.

Fixed price repair from BG might be your best bet at around 200 quid

 

[tommyr]

many thanks for the useful advice, i think i may need to clarify my second question. what i am asking there is is there any fault with the boiler that can cause a good circuit board to blow? ie could there be some other faulty component that is breaking the board and that i should also replace as well? (or get them to replace)