Potterton Suprima to Hive

hi, in October last year I fitted Hive against my Potterton Suprima boiler and it seemed all was fine. Following guidance from this site i thought i had it done. Now summer is here and I no longer need heating I’ve notice my water doesn’t get hot even though the light on the controller indicates it should. It does heat up if I have the heating on at the same time, which in the summer isn’t ideal

My wiring in the airing cupboard is shown below. Any advice on how to get hot water without turning my heating on?

I had exactly this on my Potterton Suprima. When I traced all the wiring, I found that the permanent live had been wired via the controller heat switch, so the whole system switches off when the heating is off. Fine if you can leave the heating on and just turn down the thermostat in the summer, but when you put a smart thermostat in place, you bugger it up. I don't know why it was done, but perhaps a common thing if yours is the same. I could tell you what I did, but I'm not qualified, so I'll leave the experts to give advice. Mine was wired up so that the red wire in the middle of your photo - the one that goes to the two oranges - was switched off with the central heating switch. When that's off, nothing works till you switch it back on. That's all I'll say.

Thanks David. I’m a total novice here so I must ask, which block on my picture would that red wire go too?

You need to be aware that the colour of wires in a heating system mean nothing, the only ones that mean anything in your pic are the ones from the two zone valves

Jonathon Cresswell said:

Thanks David. I’m a total novice here so I must ask, which block on my picture would that red wire go too?

Click to expand...

You see, I've already misled you and mentioned the wrong wire - sorry about that. So I'm not going to say any more for fear getting you to do something wrong. Have a look at this video, which might be relevant to your system, but you'll need to make sure this is the system you've got.

It looks like you have two zone valves, one for heating and one for hot water generation. If not then ignore what follows:
The two grey wires should be connected to permanent live then, when either valve is open, the two orange wires will become live. Beware that they could have been wired irregularly in that the orange could be live and the grey could be that which switches live when the valve is open.

Suggest you switch on JUST the heating and turn up the thermostat. Does the relevant valve open? Does it 'click' after about 10 seconds? Does the pump start and the boiler fire-up?
Next switch off the heating and turn on the HW only. As above, does the valve open, click, does the pump start, etc? No??? Then check that the brown wire which goes directly to the valve is live. If it is then it's likely the valve sync motor has failed, if not it may be that it's internal microswitch has failed. In either case the solution may be to change either the valve head or the entire valve....and from what you said about hot water only with the heating on I infer that the valve is open or partially open.
So...long story short...the valve is semi seized or the head has failed electrically.