Hybrid heating in Ottawa: a heat pump with the furnace as backup

How a hybrid system shares the winter

A hybrid, or dual-fuel, system pairs an air source heat pump with a gas furnace. The outdoor unit takes the place of a central air condenser, and its indoor coil sits in the ductwork next to the furnace. The heat pump heats in spring, fall and milder winter days, cools in summer, and hands the house to the furnace in deep cold.

Natural Resources Canada names three outdoor temperatures an installer can use to stop the heat pump:

• Thermal balance point. Below it, the heat pump lacks the capacity to heat the house alone.
• Economic balance point. Below it, the furnace is cheaper to run at current electricity and gas prices.
• Cut-off temperature. The lowest temperature the heat pump runs at.

Ottawa winters and the handover point

Ottawa’s January averages -10.0°C on the 1991–2020 normals, with about 16 nights a year below -20°C. Home Renovation Savings describes cold-climate air source units as designed to work down to -30°C, so in Ottawa the switchover is mostly a cost and comfort choice.

NRCan’s CanmetENERGY lab tested hybrids with smart switching controls in three homes east of Ottawa. The controls weighed energy prices, time of use and outdoor temperature, and used the heat pump above about -8°C off-peak. NRCan measured a 30 per cent drop in greenhouse gas emissions over a season, with operating cost in Ontario similar to a gas furnace alone. For running costs side by side, see heat pump vs gas furnace.

The furnace you keep

NRCan notes that heat pumps move more air at a lower temperature than a furnace. Before pricing, the installer looks at:

• Furnace age. One near the end of its life may be replaced in the same job; see furnace replacement.
• The blower. It has to push the heat pump’s airflow through the new coil.
• The ducts. Runs sized for furnace heat may need changes; NRCan flags airflow noise and fan energy use when the heat pump’s airflow exceeds the duct capacity.
• The panel. NRCan says an add-on air source heat pump generally needs no electrical service upgrade, though the age of the service and the home’s total load can make one necessary, and switching from gas can call for a larger panel.

Controls and the switchover setting

A control that knows both systems, usually with an outdoor sensor, decides which one runs. NRCan says the sensor is typically set at the economic balance point, chosen by the installer. Ask for that setting in writing so a later service visit can check it. Whether your thermostat can run both systems is a question for the installer; see thermostat installation.

What the quote should list

• Heat pump model, capacity in tons and its listing on NRCan’s cold-climate list.
• The indoor coil and how it matches your furnace.
• The control and the switchover temperature.
• The new circuit, and who files with ESA.
• Duct changes and removal of the old air conditioner, if any.
• The furnace, only if replaced, with its efficiency rating.
• The total with HST and the rebate the contractor expects to claim.

NRCan says sizing should follow a recognised method based on the home’s heating and cooling loads. An undersized heat pump hands over to the furnace more often. Ontario’s guide for home renovation businesses says a contract worth more than $50 needs a written agreement.

Rebates and rules, checked 29.10.2026

Home Renovation Savings pays the heat pump part only, and a participating contractor must get pre-approval before the install. The federal National Heat Pump Rebate, announced 8 October 2026, offers up to $10,000 for eligible below-median-income households and $2,000 for others; confirm it is open and covers a dual-fuel setup before counting on it. Details on the rebates page.

ESA requires a notification of work for almost all electrical work and issues a Certificate of Acceptance once the work is checked. TSSA says fuel-fired appliances must be maintained by registered contractors. The City of Ottawa exempts heat pumps from a building permit outside heritage properties.

Who you are dealing with

Ottawa Heating Desk passes your request to one independent Ottawa heating and cooling company. That company calls you, looks at the furnace and the house, prices the hybrid setup and does the install.