The thermostat could be showing a malfunction for several different reasons.
First, ensure it’s is working physically at the thermostat on the wall. If it’s not, you can find further assistance here.
If it’s working from the physical thermostat on the wall:
Have you relocated any Z-Wave devices in your home? Some of these act as a repeater for the Z-Wave signal for other devices. If any Z-Wave devices have been moved from their original location, try returning them back to where they were previously to see if the thermostat malfunction clears.
If no changes were made and the thermostat appears to be working otherwise, give us a call at 1.800.PROTECT (1.800.776.8328) for further assistance.