Is it legal (UK law) to replace the fan on a domestic gas boiler yourself?
The replacement (according to the manual) involves three screws and two blade connectors. The price of a new fan from the manufacturer is quite reasonable, the price quoted for fitting it is six times the cost of the fan!
My research so far indicates that I can do my own 'wet work' on the water pipes, radiators and pump etc. Plus I'm pretty sure I can work on the room thermostat and the external controller myself.
The regulations make it clear that I can't work on 'gas carrying components' - which I guess means the gas pipes, gas valves and burner etc.
I haven't been able to find any authoritative reference to other non-gas components in the boiler. Some sources suggest that you can't even remove the cover of your own boiler, others suggest that it's fine to remove the cover and replace switches, controllers, knobs and fans etc etc.
Anyone here able to offer any definitive advice (preferable with link to an authoritative source)
(For what it's worth, I'm a professional engineer, and probably qualify as a 'competent person')
UPDATE - the question is about which parts of a boiler can/can't be self-maintained. I know wet-work is ok, I know gas-work is not ok. What about electrical work?