In message , Ewan MacIntyre
writes
Alastair Rainsbury wrote:
It seems weird that it's only the ho****er upstairs that's not
working - if it was all the hot water, or if everything upstairs (i.e.
radiators included) that didn't work it would make more sense to me.


Alastair,

Can you hear water flowing through the combi when the upstairs taps
run? This is just a basic sanity check to ensure they are actually
plumbed in as you'd expect.

If they are, then I'd suspect that the flow control valve on the boiler
is set too low. You need to check the manual to know precisely, but on
the combi I used to have, it was on the cold inlet to the boiler, and
needed just a flat-bladed screwdriver to adjust.

The commissioning guide to combis usually advises adjusting this valve
so that turning on a tap to maximum will provide very hot water.
However, if the mains pressure changes, this setting can be wrong. I
used to just open the flow valve fully, knowing that if I turned on the
tap too much, the water would actually be cooler than if the tap were
on less.

All of this assumes that your combi is supplied with cold water from
the mains. If it is supplied from a cold tank in the loft, then you
might not have enough head to trigger the flow switch. Also, even with
the mains I suppose the pressure could simply be too upstairs?

Ewan



Hmmm, that sounds like the best bet so far. I'm now off to start
twiddling knobs/valves.

--

Alastair Rainsbury "CTID" )

Amazingly, it is illegal in all 48 US states for a railway train to be equipped
with brakes.

http://www.ignis-fatuus.org