Wire from 3port valve

[terryplumb]

If you can run hot water by itself, it suggests to me it’s been wired unconventionally, as you can see hot water alone should be the orange wire. So you’re looking possibly for the room stat live in, which could be terminal 4. Could always try the orange wire in that anyway I’d you be already tried it in a different one

When hot water alone is required ,the orange wire has no function Chris.

 

[CBW]

When hot water alone is required ,the orange wire has no function Chris.

Apologies, was getting mixed up, thinking that the orange sends swl to the boiler but that’s the cylinder thermostat

 

[BlueLoo]

This is like an electrical sweepstake.


My money is on #6...

 

[RandomGrinch]

Call me pig headed, and I could be very wrong, but I still think it's 8!

Maybe @Diytry1 can confirm/deny where the cables go from the bottom, but this is my guess...
I think the large brown wire at the front of terminal 8 goes to a pump.
Behind there, is a slim black wire. I think this, along with the blue in 7, and a brown? (appears black in photo) in 6, go to the tank stat.

Whatever these wires are, the only other choices for oranges location, appear to be 1, 4 & 6.
But I wonder how the wires came to be this way?
It looks as though the 3 port valve cable has been pulled, but I wonder if any other wiring has been changed, or was the system working properly to begin with?

 

[Johnmdc]

I would have said terminal 8 too.

 

[Diytry1]

the hot water and heating always used to run separately! Will try the wire in 4 later

 

[Diytry1]

Come home it ran for a bit now I have no power to the boiler or ch pump or hot water

 

[BlueLoo]

Blown fuse

 

[Diytry1]

Nope had to turn the hot water thermostat up for it to kick in! Orange wire is in 8 but still have to run both together! Could it be a faulty 3 port valve?

 

[terryplumb]

Nope had to turn the hot water thermostat up for it to kick in! Orange wire is in 8 but still have to run both together! Could it be a faulty 3 port valve?

You would need to do some testing with a multimeter to establish why the system isn't working ,You will need someone who can do it for you or buy a meter and do it yourself with some coaching.