After 7 months of using the T-stat, I’ve got a low battery warning. This was unexpected, since the T-stat is powered from C-wire in addition to batteries.
During those 7 months, we had a few very short power interruptions, but nothing longer than a few minutes.
Does the T-stat have any functionality that needs batteries when powering from C-wire?
Is it possible to not use batteries and suppress the warning, so that there is no need to keep replacing the batteries just to clear the warning?
While you can run the thermostat on batteries alone, it is generally not a good idea to go without them, and you should always replace low batteries when they report low.
If the batteries drain and the device loses power, the thermostat could leave the HVAC system on or off, overheating, or freezing the home.
It is odd to have low batteries show up so quickly, but one or more of the batteries may have been lower from the start.
Always be sure to use brand new batteries as replacements to ensure they all have the same charge level.