Dual-fuel heat pumps

Two machines, one house

The September 3, 2026 Dependable Grid terms describe dual fuel as an efficient electric heat pump paired with a non-electric system “to help keep buildings warm during extreme cold while reducing pressure on the electrical grid during winter peaks.” The non-electric side is oil, propane, or wood. It may already be in the building. It does not have to be bought with the heat pump. Terms, dual-fuel section

The eligible building is one that is primarily electric now, or a new home that would have been. A house whose only backup is electric baseboard is not this rebate’s dual-fuel system. A house whose primary heat is already oil is a different stream. The terms define primary heat as the permanent system sized to hold 22°C at the 2.5% January design temperature in National Building Code Table C-2. A cordwood stove or fireplace does not qualify as that primary system. Terms

What “balance point” means

NRCan calls the thermal balance point the outdoor temperature where the heat pump’s heating capacity equals the house’s heat loss. Above it, the heat pump can meet the load alone. Below it, the heat pump covers only part of the heat and supplementary heat is required. NRCan separates that from the minimum operating temperature, where the machine stops entirely. The same guide puts that cutoff, for many air-source units, somewhere from about −15°C to −25°C. NRCan heat pump guide

Yukon adds a number the listing test does not use. The heat pump must be sized to heat the entire building and achieve a balance point of −20°C or colder. Terms That is not NRCan’s cold-climate test, which is scored at −15°C. It is also not the design temperature. Whitehorse’s January 2.5% value in the NRC climatic tables is −41°C. NRC tables The rebate does not require the heat pump to carry the house alone at −41°C. It requires the machine to still match the heat loss at −20°C or colder, with oil, propane, or wood covering everything colder than that, plus any hour the heat pump is off.

When each one runs

The temperature bands are NRCan’s description of how a heat pump and supplementary heat share a load. NRCan The −20°C floor on the balance point is the Yukon rule, not an NRCan rule. Terms

There is a second switch, and it is about money. NRCan describes an economic balance point: the outdoor temperature where the backup fuel becomes cheaper per unit of heat than running the heat pump. The Yukon terms do not set that temperature. They require the heat pump to be capable of a −20°C balance point. Whether you switch the backup on earlier, because a particular hour of electricity is expensive, is an operating choice. It is not what the rebate measures.

Which backup actually counts

• Oil, propane, or wood. Electric resistance does not satisfy the dual-fuel backup.
• If the backup needs electricity — an oil furnace fan, a propane furnace, a wood furnace with a blower — it must plug into a standard outlet the terms call “110-volt,” or sit on a transfer switch, so a generator can feed it. A wood stove with no fan does not have that requirement.
• A propane fireplace has to be on NRCan’s product list at 75 percent efficiency or higher.
• Wood equipment has to be EPA-certified and meet EPA NSPS or CSA B415.10. Particulate caps in the terms: 2.5 grams per hour for cordwood stoves, pellet stoves, and inserts; 0.10 lb/MMBtu for wood boilers, or 0.15 if tested on cordwood; 0.15 lb/MMBtu for wood furnaces.

An air-source heat pump in this rebate also has to be on NRCan’s cold-climate list for Manitoba and Yukon. A ground-source unit has to be ENERGY STAR. The list is a performance screen. The balance point is a house calculation. Both are required. Terms