Heatmiser UH1-W control unit randomly calling for heat on one zone.

[dazzler9000]

Hi all, hoping somebody can help.

I have wet UFH with Heatmiser slimline RF thermostats (4 zones) connecting directly to the UH1-W control unit.

The UH1-W then connects to the boiler via Centaurplus c27 time switch, which I set to auto, as the on/off timing for the UFH is controlled by the 4 rooms stats.

I've noticed recently that zone 3 on the UH1-W is randomly on, even though the room stat is off, or not calling for heat.

Any ideas as to what the issue is here? I've already reset the room stat in question but it still does the same. I have a feeling it's the control unit rather than the room stat.

 

[dazzler9000]

I've just reset the room stat and re-paired with the control unit. I wonder if it had come up-paired and that was causing it to do weird things.

 

[MeldrewsMate]

Has your re-pairing solved your problem?
Try disconnecting the zone 3 roomstat from the UH1-W terminals....does this action make the symptoms go away?

 

[stem]

As it's been a bit colder recently, so I wonder if your symptoms have been caused by a frost thermostat somewhere. They work by overriding the normal heating controls and turning the heating on for protection of the system against freezing when the area in which they are located drops to around 5 degrees C. Although sometimes you find them set to a higher setting. With multizone installations they are often just connected to one of the heating zones.

A frost stat is usually installed somewhere unheated and where the pipework or boiler is at risk of freezing. Quite common if the boiler is in an outbuilding or garage.

If you don't have a frost stat you can ignore this post

 

[dazzler9000]

Thanks for the replies so far. I've not made it home from work yet today, so I haven't had a chance to test. My test last night looked good though. Every time that stat called for heat, the zone lit up and every time I switch it off, it went off on the controller.

I think only time and testing will tell.

I didn't notice this morning that the reset had set the frost protection back to 15 degrees, so it was on this morning, but I soon rectified that.
I'll keep you posted