Boiler puzzle

Hi,
So I opened the wiring box and located the grey and orange wires. What I have is the 2 grey wires (one from the CH and one from the HW valves) going into one terminal and then the corresponding 2 orange wires going into another terminal. So I have both of them pairing up rather than any wire going solo into a terminal. Its easy to identify which is coming from the HW and the CH but I didnt want to disconnect anything as it wasnt exactly as you described.

Do I still disconnect the CH orange wire and put it in with the 2 grey ones?

Cheers

Hold your fire! My brain is addled. Will post asap.

luke-warmwater said:

What I have is the 2 grey wires (one from the CH and one from the HW valves) going into one terminal and then the corresponding 2 orange wires going into another terminal.

Click to expand...

That's correct! Apologies for my mistake; I was working from memory.

Do you have a short length of wire which can be used to link the terminals together?

If so:

Power OFF

Disconnect both greys. and make safe.

Use the length of wire to connect the "grey" terminal to the "orange" terminal.

Make sure the HW is OFF at the programmer.

Set CH on and turn stat right up.

Turn power on

If fault occurs - boiler problem
If fault does not occur - valve problem. Probably the microswitch in the head.

OK, many thanks. I'll try that and let you know the outcome.

Just to let you know, I followed your excellent instructions and the boiler kept working so it seems that it may well be the microswitch as you suggested.

I'm going to run it like that a couple more times to confirm that the fault doesnt re-occur and assuming thats the case, I'll order a new valve head.

Very grateful for your input and for the detailed guidelines. You've restored my faith in humanity!