Wiser 3 / 2-zone system – Zone 2 valve permanently open?

[Hozier]

Shouldn't be any issues turning existing upstairs feed into a switched live.
What boiler do you have? having a pump overrun suggests it needs a permanent live.

Glow-worm Ultracom hxi - getting F11 fault now too

 

[Mister Banks]

Thanks for all the replies so far. This is the update after continuity testing:

Update: I’ve traced the wiring further and found that the problem/upstairs stat is not actually fed from the Wiser programmer at all — and, as far as I can tell, wasn’t fed from the old ESi programmer either. Instead it has a permanent live from a separate junction behind the programmer.

The working downstairs stat is different: it is fed directly from Wiser CH1, and its switched live goes to STAT 2 (3) on the PCB.

The upstairs stat’s switched live goes to STAT 1 (3), so with the old stat bypassed its permanent live is effectively keeping that input permanently called, which would explain the upstairs valve staying open.

Even stranger, continuity testing shows the wire on Wiser CH3 — previously the old ESi CH2 heating output — actually goes to P/L (pump live/run-on) on the PCB.

So:

• why would old ESi CH2 have been connected to P/L?
• can I repurpose the existing upstairs live-feed cable so it is fed from Wiser CH3 instead, making it behave like the working downstairs zone?

The upstairs zone valve switched live should be fed from the upstairs thermostat so should only be open if the upstairs thermostat is calling for heat. Even with a permanent live feeding the thermostat as long as there is no call for heat the zone valve should be closed.

 

[CarloHeatingEng]

Upstairs was never on the programmer. It was fed from a permanent live and controlled by the stat alone, which is exactly the not-zoning-correctly you suspected when you moved in. You'd already spotted it, you just had no way of knowing why.


Then you bypassed the stat, brown to black, exactly as Wiser tells you to. Nothing wrong with that on a normally wired stat. But on yours the stat was the only control that zone had. Bypass it and the permanent live goes straight through and lands back on the upstairs stat input as a call that never goes away. That's why the valve sits open the second the board is powered, and why hot water alone warms the upstairs rads.


So it isn't the actuator. It's doing what it's being told.


On why old ESi CH2 went to P/L, my guess is it was never a heating output. Somebody needed a live for the pump overrun and took the nearest terminal going. So that cable isn't spare, it's already doing a job, and I'd find out what the overrun does without it before repurposing it.


The bit I'd actually stop on is the F11. It wasn't in your first post and it is now. Get it identified before another wire moves, or you'll be chasing two faults and guessing which change caused which.


Longer term I'd do what's been said above. ESi board out, conventional wiring centre in, wired the standard way off the manuals. Sounds like more work than just re-feeding that cable from CH3, and usually isn't, and you finish with something any engineer can read. Re-feed it and you've still got someone else's wiring in there, so you'll be back here next time something goes.