David wrote:
I'm now looking back about 15 years, so I have no idea if this is still
the case.
Is there a risk that the boiler could be condemned just because it is old?
If so, February is probably not the best time to have it serviced.

We used to have one of those until about a decade ago - a big Potterton cast
iron lump.

First (90s) BG refused to cover it under their service contract.
Then they refused ad-hoc servicing as 'we'll never get parts for that'.
We went somewhere else, and it kept on working.

I'd find a good independent to service it - less likely than BG to condemn
it because they can't be bothered. But if anything breaks be prepared to
have trouble getting parts - unlike a contemporary Morris Minor there isn't
the aftermarket, unless you have someone who can machine a new one from
scratch.

Theo