Slark wrote:

I'm looking for clues on where to look with a non-working central heating
system...

The house has:

Oil-fired burner/boiler
Hot water tank
Control box for hot water/ central heating - hot water is working fine,
boiler fires up etc etc, central heating has been turned off over summer
Single room thermostat - set on high...
TRVs on each radiator - set on high...
Have bled all radiators

It *feels* like there's no signal to to boiler to say give me heat - (tho,
as I say, works for hot water)

Should there be a 3-way control valve (over and above the TRVs) somewhere
that I should be able to see?

Help...

Graham

if its firing up on HW sounds as if the pump is stuck for the CH, if
all revelvant lights say its coming on. Give the pump a nice slap with
a small hammer, mines done it a few times after being stood over the
summer months, nowadays I run it for a bit at least once a month.