Hot water has to be on for central heating to work?

[macblack]

I have a Potterton Suprima which is 21 years old, there's a tank upstairs (in the airing cupboard) which contains an integrated cold feed tank - no tank in loft. For this 21 years I've always had the hot water and central heating to on (no schedule - as there is always someone in the house, the thermostat controls the temperature.

I recently had Hive installed by British Gas and thought I would try putting the hot water on a schedule (couple of hours in the morning and evening) to save a little cash.

It got a little cold today (first time since Hive was installed) so I put the heating on and nothing! I had to put the hot water on for the central heating to work.

I know the tank in the airing cupboard stores hot water for heating and water but does this mean they can't be used independently and I should just go back to having them both on all the time?

Thanks in advance.

 

[ianmcd]

can you post a pic of your HW cyl and any controls that you have, 2 port or 3 port valves, usually near where the pump is

 

[gasbanni]

Time to modernise your heating system.

 

[macblack]

 

[macblack]

Does this help? Anyone?

 

[ericmark]

I would assume a fault, you should with most systems be able to select either DHW or CH and with old systems where this was not possible there was a switch and mechanical latch in the programmer so you could not select CH on its own.

Since I can see a tank thermostat I would assume there should be a method of independent from CH turning DHW off/on, however I see no motorised valves only two pumps, although theory you can use two pumps, in practice it is hard to stop back flow and all sorts of odd things can happen, at the moment I am waiting for a motorised valve to be fitted in my house because heating comes on when it should not.

I would call back British Gas, there is a fault, and they need to cure it, had you fitted Hive I would have started by asking how the original system worked, was it set to full 16 option mode or not, however I will guess British Gas have taken the old programmer away, so no way to check.

What you could try is turn the tank thermostat to a low setting and see if central heating works.