"Terry Fields" wrote in message
...

Simon wrote:

Many thanks for your detailed answer. I really appreciate your help.

You're welcome.

I apologise that I have to ask this, but I really don't have your
technical expertise or understanding. In your note you outline various
different valves and what they do and how their settings might be
affecting the working of the system, but from reading your answer I am
not sure which valve is which. Could you indicate which photo/s the
valve/s are in?

i think the "bypass valve" you speak of is the same as the "manual
gate valve" that Roger mentions in his reply. It was fully open and so
I have almost closed it and put the boiler on to see if that helps the
gas boiler to heat the DHW.

You have two gates valves.

One is a bypass for the heating coil in the hot water tank. It's
function is to give the pump soemthing to do when all the other
valves in the system have shut. It is the one shown in photos 2 and 8
and is on the vertical pipe that leads towards the top of the hot
water tank.

It needs to be cracked open just a little, probably half-a-turn might
be too much, but you have to start somewhere.

The other gate valve is the one that lets hot water circulate to the
radiators. It is shown in photos 3, 4, 5, 6 and has the words 'heating
valve' on the wall above it. This needs to be fully open if you want
the radiators on, or fully shut if you don't. For this experiment,
keep it closed.

I presume that the "capillary valve" you refer to is the TRV
lookalike?

Yes.

What is the optimum setting for this valve?

You set this to give the temperaure you want of the water from the hot
water taps. At the moment the valve isn't doing anything as the bypass
gate-valve is fully open and so there is very little flow of primary
water from the boiler through the heating coil. As a start, set this
TRV look-alike at mid-value. If the bypass gate-valve trick works and
the water in the tank gets hotter, then you can experiment to get a
temperature to suit you.

i'll post in about an hour to let you know if closing the manual gate
valve/bypass valve made any difference.

OK.

You appear to have a fault with the immersion heater thermostat, but
let's deal with one issue at a time. If the problems with the valve
settings can be overcome, you might not need the immdersion heater
'til spring.

many thanks for your help.

You're welcome. I hope it all works for you.

TF



Bear in mind that a thermostat for an immersion heater only costs about £8.

New ones trip out if the thermostat contacts weld together and the water
gets dangerously hot.