In a system with a condensing combi boiler with a 15mm hot water outlet and
no hot water cistern where should one convert from 15mm to 22mm pipe to
supply the bath taps? Would it make any difference to the pressure of the
water at the tap? Should the conversion be near the tap or as far away as
possible? Or does it make no difference?
The shorter the length of 22mm, the less cold you will have to run off
before getting hot to the bath so you get faster warm up. If you leave a
couple of metres of 22mm then you may get a water hammer type clunk when
the bath or sink tap is closed quickly, most likely caused by a shock
wave hitting the 22/15mm transition so it's a good idea to take 15mm
right up to the taps, plastic pipe is good for doing retrofits of this
At mains pressure I wouldn't worry about 15mm causing a restriction in
flow at much less than 10m.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.