Although I clearly already have my answer (thanks!), below is a picture of the pipe outside - just FYI. The original copper pipe is mid-way between the flue and the new plastic pipe.
The boiler was is nearly two years old and hasn't yet been serviced - that's happening in the next fortnight. It was fitted by a bloke I didn't like (he was lazy and a liar), but he was definitely fully qualified and was a "friend" of my mum's.
The boiler was is nearly two years old and hasn't yet been serviced - that's happening in the next fortnight. It was fitted by a bloke I didn't like (he was lazy and a liar), but he was definitely fully qualified and was a "friend" of my mum's.