A dual-fuel system pairs an electric heat pump with a gas furnace in one ducted system. The heat pump handles cooling and most heating, and the controls switch to the furnace below a set outdoor temperature, called the balance or changeover point, or when the heat pump cannot meet demand. Only one heat source runs at a time.
Why it matters to you
In the Fraser Valley the heat pump can carry most of the mild, damp winter, while the gas furnace covers the occasional hard cold snap. It suits homes that already have FortisBC gas service and sound ductwork, and lets owners weigh BC Hydro electricity against FortisBC gas for heating.
Practical guidance
Ask how the changeover temperature will be set and whether it can be adjusted later as rates change. If you are counting on a rebate, confirm in advance how the program treats a system that keeps the gas furnace.
When does a dual-fuel system make sense?
It fits best where a home already has gas service and good ductwork, and the owner wants heat pump efficiency and summer cooling without giving up gas heat for the coldest mornings. It can also be a way to add a heat pump to a furnace that still has useful life left. Homes with no gas service usually look at an all-electric heat pump with electric backup instead.
How is the changeover temperature chosen?
The changeover point is set where the heat pump either stops keeping up with the home's heat loss or stops being cheaper to run than the furnace. That depends on the heat pump's low-temperature capacity, the home's heat loss, and the relative cost of BC Hydro electricity and FortisBC gas. Because rates change, a control that can be re-set later is worth asking about.
Does a dual-fuel system qualify for BC heat pump rebates?
It depends on the program. Rebates aimed at switching a home away from gas, oil or propane may treat a system that keeps the gas furnace differently from a full conversion. Program rules change between years, so confirm eligibility for the exact configuration before the install is booked.
What should a dual-fuel quote include?
The heat pump and coil model numbers, how the existing furnace will be integrated or replaced, the control that manages changeover, the electrical work, and any ductwork changes. Sizing should come from a heat-loss calculation, because the heat pump's share of the winter depends on it being matched to the house.