Charles F wrote:
We had the same problem with an ensuite in an extension at the "wrong" end
of the house from the hot water source, and a pipe run of maybe 20 metres.

Initially a hot and cold run in 15mm PEX - shower delay to hot quite
reasonable, but hot tap in the basin took an eternity, esp. in winter.

Solution was a separate hot feed to basin in 10mm PEX, well insulated, which
reduced the delay to less than 40% of that with the 15mm. Flow to the tap,
with initial pressure (via pressure reduction valve) of 3.5 bar, perfectly
reasonable for hand washing.

Simple, cheap, no ongoing costs

It still costs to heat the water. Depending on how much heat you
'lose' by heating the water in the pipe each time (agreed, it's less
with a smaller pipe) it could still be cheaper in the long run to have
'locally' heated water. There's also the cost of any wasted water to
take into account if you're on a meter, though I'd guess that's pretty
trivial.

Whatever, it's the lovely, near instant, availability that we like
with our under sink heater. Even if it was costing a little more
(which I doubt) we'd go for it. Initial cost was very little,
something like £70 I think and I plumbed it myself so that cost very
little indeed.

--
Chris Green
·