What happens when winter temperatures plunge and electric heat pumps can’t keep up? It’s a question more builders are asking as these systems grow in popularity.
Many are finding a proven solution: pairing a heat pump with a propane-fueled furnace or hydronic heat pump for reliable, year-round comfort.
Eastern Propane, operating in New England where heat pumps struggle during cold snaps, is seeing rising interest in dual-fuel systems. “The heat pump just can’t pull enough heat out of the air when it’s below freezing,” explains Moose Harte, manager of Eastern Propane’s residential construction services. “You need another heat source, and a propane furnace is a great way to go.”
Advantages of Propane Backup
Propane backup systems offer several key benefits:
- Reliable performance: Unlike heat pumps that lose capacity in when temperature fall below 40, propane furnaces maintain high efficiency (95–98%) regardless of outdoor conditions. So-called “cold-climate” heat pumps maintain temperature to below 0-degree F. but cost significantly more and still won’t deliver enough heat during cold snaps in winter, like we saw across the northern states in 2024-2025.
- Grid resilience: Propane systems reduce reliance on the electric grid—especially important in rural areas or locales prone to power outages.
- Cost control: Dual-fuel setups help manage energy costs by using efficient heat pumps in milder weather and propane when temperatures plunge.
The Air-to-Air Heat Pump Approach
Most dual-fuel systems today combine an air-source heat pump with a propane furnace. In this configuration, an outdoor heat pump condenser replaces a traditional air conditioning unit, while a propane furnace takes over when temperatures drop too low for the heat pump to operate efficiently.
“We see the heat pump as ideal for shoulder seasons—spring and fall—when you just need a little heat,” says Ryan Klopfenstein, technical trainer at Eastern Propane. “But once it gets down to 30 degrees or lower, that propane furnace kicks in to keep the house warm.”
Hydronic Heat Pump Solutions
The hybrid hydronic heat pump solutions, such as the Heat Pump Helper and the Heat Pump Companion, are other options offering an innovative approach to home heating. This set-up integrates a propane tankless water heater with a home’s existing air-source heat pump system. When outdoor temperatures fall below 40°F, the system activates the propane-powered water heater to circulate hot water through a hydronic coil within the air handler. This process delivers warm air through the home’s ductwork, providing efficient and comfortable heating without relying on electric resistance heat strips. By utilizing propane in colder conditions, homeowners can achieve up to 35 percent savings on heating costs compared to all-electric systems, while also benefiting from improved performance and reduced electrical load demands.
Retrofitting Existing Homes
While new construction is a key focus, retrofitting existing homes with dual-fuel systems is gaining traction. Homeowners frustrated by high electric bills and insufficient heat during harsh winters are increasingly open to propane backup solutions.
Cost remains a primary concern. Builders often weigh the upfront price difference between mini-split systems and dual-fuel installations. “A lot of builders assume mini-splits are cheaper, but when you add multiple heads and factor in labor, it can cost as much as a conventional propane system,” Harte notes.
The Reality of Incentives and Grid Impact
Utilities are heavily incentivizing all-electric heat pump installations, but the reality is more complex. “Nobody’s really studied how much strain this is going to put on the grid,” says Harte. “Yet utilities keep pushing for more electric installs.”
Adding propane backup can also help avoid costly electrical upgrades. “Heat pumps require larger electrical panels and significant power draw. With propane, those costs can be avoided,” Harte says.
The Bottom Line: Practical Efficiency
For homeowners and builders in colder regions, dual-fuel HVAC systems offer a balanced solution, leveraging the efficiency of the lower-cost heat pumps in mild weather while ensuring reliable warmth with propane during deep freezes. It’s a practical approach that delivers comfort, cost savings, and energy resilience.
“Dual-fuel systems are practical,” Harte says. “They have their place, especially here in the Northeast where winters are no joke.”
Learn more about how builders are incorporating clean, energy-efficient propane into their projects.
