Do Heat Pumps Really Work in Cold New England Winters?

If you’re considering switching from oil or gas heat to heat pumps to heat your home, you’ve likely talked to at least one person who’s said they don’t work in extreme cold weather. This may have been true in the 1980s, but the technology has evolved. The current generation of cold climate-ready heat pumps can handle even the coldest winter. In fact, heat pumps heat over 60% of the homes in Norway; closer to home, the 2024 Massachusetts Climate Report Card estimates that over 90,000 homes have installed heat pumps as their primary home heating source (more, if you count homes that did not use Mass Save®).

What about earlier generations of heat pumps?

It’s true that earlier heat pumps sometimes failed to produce the efficiency gains they promised, and sometimes failed to heat the spaces enough for comfort. This had a few causes:

• Early heat pumps ran at full capacity regardless of environmental conditions. Because of this, they were likely to overshoot their set point or desired temperature, causing them to turn on and off as the indoor temperature moved above and below the set point.
• The technology had not yet matured. Early generations of heat pumps did not have variable-speed compressors or reverse cycle defrost, two features that make effective heating possible even in extremely cold outdoor temperatures.
• Design and contractor issues—Not all contractors are equal. People often blame the heat pump technology itself for failures in efficiency, when performance issues may have been caused by poor design, such as oversizing the systems for the space they’re heating.

Cold-Climate Heat Pumps

Modern cold-climate heat pumps include features that were not available even a decade ago, such as variable-speed compressors and improved defrost-cycle controls. Today’s cold-climate air source heat pumps work in very cold weather, and are used as the primary heating source for homes in Vermont, Maine, upstate New York, and of course Massachusetts. In fact, a 2021 Whole Home Heat Pump Study done by DNV for Efficiency Maine showed that heat pumps perform well in homes of varying ages and sizes and in all seasons.
The same study showed that using heat pumps generated real cost savings in the winter. One family the study tracked saved $2000 in heating bills during a six-month time, compared to what they would have paid to heat with their oil furnace.

Do problems still occur today?

Problems that occur today are typically not due to heat pump technology itself, but to the wrong equipment, poor installation, undersized or oversized systems, or inadequate home insulation. On the subject of insulation, utility incentive programs such as Mass Save® will provide rebates for heat pumps only after it’s been demonstrated that a house is properly insulated.
It’s also super important to use a qualified heat pump installer. The refrigerants used in heat pumps and air conditioners are in fact greenhouse gases. The linesets that carry the refrigerants are a common location for leaks, something that can be avoided by installing them properly.

Do cold climate heat pumps have a sweet spot?

Cold-climate heat pumps can be used as a primary heating source in homes all over Massachusetts. They are an economical choice if your building is currently heated by oil or electric baseboards. Because of the low price of natural gas, they will not always pencil out right away when switching from gas heat.

What should you do to be extra cautious?

If you choose the right equipment for your home, make recommended weatherization upgrades, and hire a reputable contractor with experience installing heat pumps, you should have a good outcome. As part of the Mass Save Heat Pump Installers Network, McMahon’s trained and qualified installers provide reliable, high-quality installations crucial for meeting performance and safety standards.
If you have a boiler, furnace, or electric baseboards in place, you can leave them operational as a backup heat source. In this scenario, your furnace, boiler, or baseboards will only switch on when it gets extra cold.

Keeping your cold-climate heat pump working well

Regular maintenance should be performed at least once a year to check for refrigerant leaks and to make sure your system is functioning well. You should set the thermostat at a constant temperature rather than turning it up and down with shifting weather or comfort needs.

So, do heat pumps work in cold New England Winters? Absolutely — modern heat pumps are not your grandfather’s heating system. They’re efficient, reliable, and built for weather all the way from New England to the Arctic Circle. If you’re curious whether a heat pump makes sense for your home, we’d love to chat. From the first conversation to annual maintenance, our Boston-based plumbing and heating team is ready to keep you warm all winter long.