"keith" wrote in message
...
Please can someone help me tell if our CH is faulty or if i've just got
the settings wrong?
There are more knobs to fiddle with on than the CH in our previous house
& I'm not sure what thay do or how they interact.
Pictures at :

www.dulwich.net/ch

CH works OK during day on timer, but seems to "go to sleep" at night (even
when timer says ON and thermostat is calling) and won't get radiators
warm. Also doesnt start warm in the morning. Plenty hot during day!

I've managed to "wake it up" last 2 nights by 1-Switching programmer on &
off at mains or 2- turning up the knob on the water tank.

I can work the thermostat and timer (just like old house) but this one
also has a big knob 0-5 on the gas heater (see pictures) which makes the
gas flame appear & go higher sometimes, other times turning it up has no
effect - no flame to be seen.

What is this knob supposed to do & what should I be doing with it & how
does it interact with the knob on the water tank, which I think is the
water temperature?
(see pictures)

Have I got one of these knobs too high or something to cause the problem?

Thanks

I'd guess that if you look (usually in the airing cupboard) you will find a
motorised valve with three pipes into it and a metal or plastic box
containing the drive motor attached to it. Possibly the motor has died at
some time and someone has pushed the drive unit override lever across into
the manual position which sets the valve to pass hot boilerwater to both
cylinder and radiators. As the motor does not drive the valve all the way
across the internal limit switch does not operate to call the pump and
boiler into life. Turning up the water thermostat or running off some hot
water thus calling for heat to the cylinder does ask the boiler and pump to
operate and so you get heat to your rads.
See the faqs for Y plan systems. Replacing the failed motor is a fairly
trivial job and inexpensive
Of course you could have an incorrectly wired system (g)