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TheScullster TheScullster is offline
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Default combi DHW supply/flow pipe size


"Anita Palley" wrote


On my combi the tail at the bottom of the boiler for taking cold water
is 15mm, and so I guess is the pipework within the boiler. In this
case I can't see any benefit it having 22mm pipe from the main, or am
I missing something?

Yes

15mm pipe from the stoptap to the boiler with associated elbows etc creates
a pressur drop.
Using 22mm right up to the 15mm boiler connection guarantees minimal losses
before the boiler.

Phil