How to Use Your Heat Pump During the Extreme Cold

How to Use Your Heat Pump During the Extreme Cold

When a deep freeze hits, your heat pump becomes the quiet workhorse keeping your home comfortable. Cold-climate heat pumps are built for low temperatures, but using them the right way can make a real difference. Here’s how to help your system perform at its best during extreme cold. 

1. Set It and Leave It (Your Heat Pump Prefers Stability)

Heat pumps work differently from traditional boilers and furnaces. Instead of firing short bursts of high-temperature air, they perform best when maintaining a steady, consistent indoor temperature.

During extreme cold, avoid large temperature setbacks. Turning the thermostat down too far forces the system to work harder to recover in frigid conditions.

Do this instead:

• Choose a comfortable temperature and keep it steady
• Avoid lowering the thermostat dramatically overnight or while you’re out
• If you want to save energy, adjust the temperature by 1–4°F, not 6–10°F

Keeping a stable set-point helps your heat pump operate efficiently and prevents unnecessary strain during the coldest hours.

2. Keep Indoor Airflow Clear

Your heat pump relies on steady airflow to deliver heat effectively. When filters or vents are blocked, the system has to work harder — especially during extreme cold.

A quick check can make a big difference:

• Ensure no furniture, curtains, or décor are blocking indoor units or vents
• Clean or replace filters regularly — at least every 3 months, and more often if you have pets or allergies

3. Help Your Outdoor Unit Stay Clear

Your outdoor unit is exposed to wind, snow, and ice — and continues working through it all. Giving it some breathing room helps it operate more efficiently.

During a cold snap:

• Maintain 18 inches or more of clearance around the outdoor unit
• Gently brush snow off with a broom (never a shovel)
• Don’t chip or pry off ice — the unit will go into defrost mode to handle this on its own
• If freezing rain or heavy snow is forecast, check on the unit periodically to ensure it’s not buried

Keeping the outdoor area clear helps prevent airflow restrictions and supports proper defrost cycles.

4. Know What’s Normal in Extreme Cold

Heat pumps behave a little differently when temperatures plummet. Many signs that homeowners worry about are completely normal.

Normal behavior includes:

• Longer operating cycles — the system may run almost continuously
• Steam rising from the outdoor unit — this is part of the defrost process
• Lower, but still comfortable air temperature coming from the indoor unit

Call a technician if:

• The outdoor unit is fully encased in ice with no signs of melting during defrost cycles
• You hear loud or unusual noises coming from the system
• Your home temperature drops more than 3–4°F below your thermostat setting.

Final Thoughts

Cold-climate heat pumps are built for the kind of winters we get here in New England, and they’re incredibly reliable when you treat them right. With a steady thermostat, good airflow, and a quick look outside after big storms, your system will keep you warm and comfortable even on the coldest days.

And if something doesn’t seem quite right or you just want a second set of eyes before the next cold snap — Forge is always happy to help.