In article <515b33ab$0$1142$
5b6a...@news.zen.co.uk>,
I bought a length of clear poly tubing to couple my boiler to the
22mm (or 21.5mm) waste pipe. This was partly so I could see if it
was producing condensate, and partly because servicing requires
disconnecting it at the boiler end to remove and clean the internal
U-trap. It was a tight push fit over the overflow pipe. I think
I got it from B&Q from their cut lengths section, but that was 11
years ago. I don't know if B&Q still do it, but an aquarium/pond
shop would be another option.
Tubing of this size isn't cheap, but I could buy just half a metre.
At the other end, I have a T'ed into the 32mm basin runaway, with
a 32-22 reducer. The basin U-trap has an integral AAV to prevent
the basin emptying from sucking the boiler's U-trap empty.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]