Dodgy boiler wiring

[rr755507]

Hi,

Have a problem with the conventional boiler on S-Plan with 2 zone valves. The HW is not firing when requested on the programmer. Opened up the junction box and all came clear, its a mess, instead of using the 2 way valves switches, the live from the CH programmer has been wired to switch the boiler on, whether or not the thermostats are calling for heat. The HW from the timer goes nowhere...

The question though, is would anybody like to hazard a guess what the hell the cable with the question mark is going to / doing?
Its a 3 core wire going into the fabric of the house so cannot easily trace it, it's not a frost stat or immersion. Floating neutral to a 2 way hall switch?

Diagram here (earths exist I just haven't bothered drawing them in)

Untitled

• rr755507
• 22 Apr 2012
• 1

 

[EFLImpudence]

Whatever it is it isn't doing anything - connected to a ring to both valves and back.
Disconnect it and insulate the wires.

Is there voltage on it.

You need a live from programmer to wiring block.

Then rewire it all.

 

[sparkiemike]

That diagram is NOT s-plan!

I would say that the ? cable it should be a live connected to the grey wires on the 2-port valves.

Also the orange wires from the valves should be connected to the SL on the boiler. The cabling between the stats and the valves is also wrong.

As said start again

 

[rr755507]

Whatever it is it isn't doing anything - connected to a ring to both valves and back.
Disconnect it and insulate the wires.
Is there voltage on it.

Thanks, disconnected with no effect and no, no voltage on it.