Before starting to fit a new kitchen, the fitter turned off the CH+HW,
then disconnected and bypassed the kitchen sink.
We were out last evening, but the heating didn't switch on this
morning, which has me concerned.
Another point, I left the thermostat on ~15degC overnight and the
heating on; around midnight, there were strange gurgling noises
compeletely unlike anything I've heard before from the system, so I
just turned everything off and went back to bed.
I'm waiting for the fitter to arrive this morning, so I can find out
what sequence he followed, but what I've tried is:
- ensuring the stop-cock that feeds the pump is fully open
- starting up the HW and CH independently (we've had issues before
where HW would come on and not the CH, but it's been fine for a while
and wouldn't want it to become a red herring)
- turning up the wall thermostat to max

I can hear the pump chrning away, but no change has resulted, the
system doesn't appear to be heating up either water or rads.
Boiler is in the garage, soI'll go out and check it's lit when I've
written this, but can't see that being the likely problem.

Could an air-lock have been introduced when the fitter turned off the
system initially ?