"Bob Mannix" wrote in message ...

-8- snipped -8-

There should be a thermostat on the cylinder between, vertically speaking,
the boiler pipes. This will open the motorised valve and request heat from
the boiler (if the water switch is ON) when the water temperature drops.
There must be a heating/water control panel somewhere (behind a cover in the
boiler or on a wall somewhere).

There are some 'boxes' with electrical feeds strapped to the side of
the cylinder with what looks like the wire cord used to hold up net
curtains. One of these has a dial on it, and from your description
I'm willing to bet (a small, nominal amount!) that that is the
thermostat. There doesn't appear to be any 'kettling' whan the boiler
(rather than the electrical system) is running the DHW.

Control panel - do you mean the dual hot water and central heating
timer panel that's in the kitchen downstairs?

The big question is "why was the water circuit valved off?". I fear I can't
imagine anyone doing this unless there was a problem! One likely problem (if
there is one) is a leak between the heating coil in the cylinder and the
DHW. If you run the system as it is intended, and there is a leak,
eventually the DHW cold header tank will overflow (the pump pressure forces
water from the boiler circuit into the DHW and "backfills" it). An
unscrupulous seller might have just valved off the tank and switched to
electric heating and not said anything. OTOH they may just have been stupid
and not realised it was valved off! I hope it's the latter.

It wasn't actually turned off - it was open, but only just. All I've
done is open it by a further half-turn or so. I take your point,
however, about possible causes for that, and I'll chek the area for
leaks as soon as I get home.

WRT to DHW header tank - presumably this would have to be physically
sited higher than the top of the DHW cylinder? Is it possible the
cylinder is fed at mains pressure? I ask because there is only one
header tank in the loft area (that I have found) and that is level
with the cylinder (the bottom of the tank is level with the bottom of
the cylinder - I guess the top of the water level would be about level
with the upper boiler pipe). I suppose I can check to see if this
fills the tank by seeing if the ball-valve opens when a hot tap is
turned on...

The kettling will just be an auditory annoyance but it may still be worth
checking the immersion heater thermostat.

Aye, will do as soon as I get home. As I said before, at least I know
what I'm loking for now...

-8- snippety-do-dah -8-

Good luck.

Heh, thanks - I sincerely hope I don't need it! Actually, I'm
starting to enjoy this - it's amazing how quickly you start to
understand things once you get over the fear...

Cheers - Adam...