The3rd Earl Of Derby wrote:


You want an increasing adaptor for the liner.
http://tinyurl.co.uk/10es


--
Sir Benjamin Middlethwaite
Thanks for that. I have since spoken to an installer and apparantly
there is a limited range available for fitting to a 4 inch pipe so I
will follow that up. My only concern is that knowing how funny gas regs
are would an installer fit a fire designed for a 5 inch flue to a 4
inch flue. Although it is only 1 inch on diameter that is 36% reduction
in surface area.
I assume that these things are that way for a reason. My symplistic
mind would assume that the gas velocity in a larger diameter flue would
just be less than the smaller diameter flue. The old gas fire worked
perfectly ok.

Kevin