Exactly and as I am not stupid! I am sensible and competent I will not be touching or moving the gas connector or pipes in any way shape or form.
I can buy a Glow-worm 801310 PCB and Thermostat 800999 for £110.00 and fit myself, Better then paying over £200 from glowworm. This depends on the full exact problem. I can follow instructions / diagrams.
You have already said that you can replace the PCB yourself but that will involve disconnecting a gas supply between the firs and the boiler.
As you are not stupid, you will know that these two of your statements cannot both be true, so one of them is not true.
My guess is that you DO intend to replace the PCB and disconnect the gas connection.
We do not give advice on DIY gas work here!
Tony