GLOW WORM ULTRACOM2 30CXI

[katsimba]

Hi all

We have a Glow Worm Ultracom2 30cxi, it operates off 2 heating thermostats, upstairs and downstairs.

The issue we have is that the downstairs in constantly on, belting hot, even with the thermostat turned down to 5 deg or even turned off, the only way to turn the downstairs heating off is to turn the heating off by the boiler.

The upstairs operates fine with the thermostat, unless the heating is turned off by the boiler itself.

I have spoken to our regular engineer and he has said its a thermostat issue and we need a new one, however another engineer has said its a zone valve issue, saying we should have 2 zone valves near the boiler which I cannot see anywhere, and I've also spoken to Glow Worm who have said its "more than likely" a thermostat issue.

Both the thermostats are wired.

Any advice would be appreciated, thanks in advance
Keith

[gas4you]

Sounds like a zone valve fault to me.

Either stuck open or the microswitch in the head has failed to on.

Check your airing cupboard for two zone valves, near the floor if they are there.

[katsimba]

Thanks Dave

I’ve had a message back from the home builder saying both zone valves are located in the stairs I’ll head behind a white panel so I’ll have a look when I get home.

Strange that glow worm are telling me it’s not that as it’s a combi and will therefor be the thermostat

Thanks again
Keith

[gas4you]

You must have two zone valves as it is zoned.

If one is stuck open the manual leaver will be able to be moved with no resistance.

If both shut, then you need to see which orange wire is live to determine which switch is faulty.

Only test this if you are safe to do so as you are testing 240VAC which can kill!