Best Winter Thermostat Settings for Colorado Homes

“What should I set my thermostat to?” has a different answer in a Denver townhome with a gas furnace than in a Boulder house with a heat pump, and a different answer in a mild January week than during an arctic outbreak. Here is how to pick settings that are comfortable, safe for the house and actually lower the bill.

The starting point: 68–70°F

DOE’s winter guidance is to set the thermostat as low as is comfortable while you’re home, starting around 68–70°F and adjusting from there. Xcel Energy recommends 68°F or lower to save energy. Colorado’s dry winter air can make 68°F feel cooler than the same setting in a humid climate, so a little humidity, warm socks and a ceiling fan on its winter (clockwise) setting go further than raising the setpoint.

Setbacks: how much, how long

A setback is a lower temperature while you sleep or are away. DOE says a 7–10°F setback for 8 hours a day can save up to about 10% a year on heating and cooling. The physics is simple: a house loses heat in proportion to the difference between inside and outside, so a cooler house loses heat more slowly. The furnace does run longer to recover, but that recovery uses less energy than holding the higher temperature all night.

Gas furnace homes

• Use 6–10°F setbacks overnight and during the workday.
• Schedule the warm-up 30–60 minutes before you wake up or get home. Multi-stage and modulating furnaces recover more quietly on low fire if you give them time.
• In an arctic cold snap, shrink the setback or skip it. At −10°F, a furnace sized for the 0–5°F design temperature may run nonstop and still take hours to recover. More in furnace can’t keep up in extreme cold.

Heat pump and dual-fuel homes

An older DOE tip sheet warned: if you have a heat pump, don’t set it back without a programmable thermostat. The reason is backup heat. When a heat pump has to raise the house several degrees quickly, many thermostats bring on electric resistance strips, which cost far more to run than the heat pump itself.

• Use small setbacks, about 2–3°F, or none.
• Use a thermostat with heat pump “smart recovery” or adaptive recovery that warms up slowly on the compressor.
• In a dual-fuel system, check the balance-point setting so the gas furnace, not electric strips, handles deep-cold recovery.

Colorado specifics

Xcel time-of-use rates

Many Xcel Colorado customers with smart meters are on time-of-use rates. Under the schedule regulators approved in 2025, on-peak is 5–9 p.m. on non-holiday weekdays, all year, with lower off-peak prices. If you heat with a heat pump or electric baseboard, let the house warm a degree or two by late afternoon and coast through the on-peak window. Gas furnace homes are mostly unaffected, since the blower is a small electric load. Check your own bill for the plan you’re on.

Sun and altitude

Clear winter days at 5,000-plus feet bring strong sun through south and west windows. A thermostat near a sunny window can satisfy itself while the rest of the house cools. Move the thermostat, add a remote sensor or schedule around it. Uneven rooms are covered in why one room is colder.

Away for the holidays

Leave the heat on at 55–60°F, open sink cabinets on outside walls, and ask someone to check the house during a cold snap. A Wi-Fi thermostat that sends a low-temperature alert is cheap insurance. After a power outage, smart thermostats may reboot without their schedule; see power outages in a Colorado winter.

Thermostat settings at a glance

Three thermostat myths

“Cranking it to 80 heats the house faster.”

A furnace delivers heat at one rate (or a few, on staged models) no matter how high you set the thermostat. A higher setting only makes it run longer and overshoot. Set the temperature you actually want.

“It costs more to reheat than to leave it alone.”

Not with a gas furnace. The house loses less heat while it’s cooler, and that saving is larger than the extra run time during recovery. The exception is a heat pump that recovers on electric strips, which is why heat pumps get small setbacks.

“Closing vents in empty rooms lets me set the thermostat lower.”

It usually backfires. A Berkeley Lab study measured higher, not lower, energy use with registers shut, because the ducts leaked more under the extra pressure. Leave registers open and use the thermostat schedule instead.

Comfort without turning it up

• Add a little humidity. Very dry Front Range air makes the same temperature feel colder. A whole-house humidifier set modestly, so windows don’t fog or frost, can let you keep the setting a degree lower.
• Seal the drafts you can feel. Weatherstrip doors and attic hatches, and add foam gaskets behind outlet covers on outside walls.
• Use the sun. Let low winter sun in through south windows, then pull the shades once it sets.
• Replace the filter. A clogged filter cuts airflow and makes the furnace run longer for the same comfort.

Step-by-step: program it once

When the thermostat isn’t the problem

If the house never reaches the setpoint, cycles constantly or the thermostat display goes blank, the settings won’t fix it. Start with thermostat not working, and book furnace repair or heat pump repair if it’s the equipment. MrFixer also installs and sets up smart thermostats, including heat pump recovery and dual-fuel settings. Call (720) 466-7983.