Gas pipe question?

24 Jan 2006
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United Kingdom
Looking into having a new boiler fitted but the old one (House build~1980 and boiler from new) has a 15mm supply coming out of the wall under it. Reading up, boilers require 22mm supply, is there any new condensing boilers which can run off my old 15mm supply and any recommendations?

Failing the above would they have run a 22mm from the supply and then scaled down for the hob and boiler? I'v had a nose in the box at the front of the house but cant really see. Would this pipe be run through the cavity to the back of the house or would they have run it under the floor boards upstairs to the back then dropped down?
Sorry another question - If i needed a new supply run how would they run it? Would it mean ripping all my floors up upstairs?

Any help would be great :D
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Its often possible to run the gas supply pipe on the outside of the house.

It should not be fitted within a cavity.

A gas engineer would be able to measure the pressure drop with the existing boiler and then calculate whether the existing gas supply is adequate for the proposed new boiler. Nothing much we can do or say without looking at your house.
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