Thermostat settings by state
Thermostat settings in Maine
By Ismail Farooq · Updated 2026-10-30
How most homes heat: Heating oil boilers in most homes, with fast growth in cold-climate heat pumps; wood and propane are common too.
Maine has one of the highest shares of homes heated with oil in the country, mostly through boilers and hot water baseboard. Those systems usually have two-wire thermostats, so a smart thermostat needs a power plan; see smart thermostats on a boiler.
Maine has also added cold-climate heat pumps faster than almost any state. Many homes now run a ductless heat pump for most of the winter and keep the boiler as backup. Make sure the two don’t fight: set the boiler’s thermostat a few degrees below the heat pump’s, so the boiler only runs when the heat pump can’t keep up.
Climate zones in Maine
| Place | IECC zone |
|---|---|
| Portland | 6A |
| Augusta | 6A |
| Bangor | 6A |
| Caribou | 7 |
Zones follow county lines on the 2021 IECC map, and some counties changed zone between code editions. DOE’s Building America climate zone map lists every county.
Starting settings
- Everyday setpoints: about 68 °F in winter and 78 °F in summer while you’re home, set back while you sleep or are out (DOE’s guidance).
- Gas, oil or propane furnace or boiler: setbacks of 7 to 10 °F are fine; use the thermostat’s early-start feature so the house is warm on time.
- Heat pump: keep winter setbacks small (2 to 4 °F) so a cold morning doesn’t bring on aux heat.
- Freeze protection: keep the away or minimum temperature at about 55 °F or higher in winter, and make sure the thermostat keeps working without Wi-Fi.
Heat pump lockouts for Maine
If you have a heat pump, these are starting points for the outdoor temperatures that control backup heat. Your installer’s balance point is better if you have it.
| Zone | Aux heat lockout (electric strips) | Compressor lockout (dual fuel) |
|---|---|---|
| 6–8 | From the heat pump’s rated output at low temperatures; cold-climate models often run well below 10 °F | Often 0–25 °F, from the installer’s balance point |
Rebates
Many utilities give rebates or bill credits for smart thermostats, sometimes in return for joining a peak-day program. Programs change often, so check your electric and gas utility’s website, or search by ZIP code in the ENERGY STAR rebate finder.