Heating with a mid or high efficiency propane or natural gas furnace? If you plan on leaving your home or cottage for an extended period of time during the heating season, you should only reduce your thermostat to 16 degrees C (60 F) to prevent damage from the following:
- Return air temperatures are too low, and condensation will form on the primary heat exchanger. This causes corrosion and leads to premature failure
- Outside air temperature can cause freezing of the condensation after the secondary heat exchanger. This causes cracking and can lead to water leaks damaging the electronic control board of your furnace.
To prevent expense repairs, leave your thermostat set to 16 C (60 F) or higher. If your furnace fails completely due to freeze-up, the results could be a frozen dwelling with split pipes leading to tremendous water damage.