If you replaced the batteries on your CT3200, CT3300, T8112, T8132 thermostat and are still getting the LOW BAT message, follow these steps:
1. Remove the batteries from the thermostat and place them in the opposite / wrong / incorrect position in the thermostat place the (+) on the (-) and vice versa).
2. Leave the batteries like that for 30 seconds.
3. Remove the batteries and place them back to the correct position.
4. Your thermostat should reboot and the LOW BAT message should be deleted.
5. If your thermostat does not light up after this procedure, you might have a defective thermostat. Consider replacing your thermostat.
6. Make sure that you are using alkaline batteries on your thermostat. Other type of batteries, such as rechargeable or lithium batteries will not work properly in the thermostat.