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