Could be worth giving British Gas a call, I know they’re expensive but they do a repair and cover option that might help you out.
We called them out this week as the noise from our pump became too unbearable, £99 to fix the first issue and then £21 a month for 12 months (no excess) and a free boiler service ever year.
Guy put in a new pump and then went to service the boiler and told us that’s shot too! We knew it was leaking a bit (rusty water too) so no great surprise. Because of this they can’t cover us until it’s fixed or replaced (we won’t be using them to replace it). Anyway, they’re going to bill us for the pump and cancel the contract, the bill will be on a par with what I was quoted by local plumbers.
So if you have just the one fault (with the boiler) and were thinking about getting cover anyway, it might be worth giving them a call.