"Tony Bryer" wrote in message
...
In article , Nick
Brooks wrote:
The 28 HE cannot use
plastic drain piping for the flue.

Very interesting but not relevant as original poster hasn't got
a 28HE

Who said anything about drain piping, this is uk.d-i-y not
uk.bodge-it

Keston (and IIRC one or two other) boilers use 50mm muPVC plastic
waste pipe for their air intake and flue. £10 or so for 4m, a
fraction of the cost of most flue extension packs.

If you use the flue extensions to their maximum length and the odd elbow,
they can cost more than the boiler.