No battery warning from hard-wired Wall Smart Thermostat’s

Hi all,

Just wondered if anyone else has had this issue like me?

I recently went to a wall thermostat to check the room temperature and noticed the display was not working correctly and very erratic. I checked the device in the app but it was showing the batteries as been “good” and the device also still controlled the heating circuit.

I replaced the batteries on four of the five Thermostats and all display correctly now.

Still not sure why the battery warning never appeared?



  • I had exactly the same problem!

    Batteries were low, but not flat, but no indication of this In the app - the display simply kept behaving erratically. Changed batteries and hey-presto working propery again!

    I guess ther battery level checks are not working as they should?

    Thanks for the tip - saved me loads of stress!

    Best Regards, Steve

  • FrankFrank | Admin


    This is an issue we are working on resolving.

    What happens is that the voltage is OK, enough for normal operation (communication, switching etc.), but when the display is activated, the voltage drops so low as to restart the thermostat.

    This won't trigger the low-battery warning however, because the voltage goes back above the threshold as soon as the display is off, so the next time it reports in, the voltage is fine. But because it gets restarted by the sudden voltage drop, it can't remember that it had a problem with the voltage.

    It's a bit of a catch-22, but we know the cause so are hopeful to have it resolved. Just FYI, we only get a report of this once or twice a month, at most, so it is also a rather rare occurrence.

    Best regards,


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