Guide · Heat pumps & rebates
Radiant floors and heat pumps, explained for Ontario homes.
Radiant floors run on low water temperatures, and that’s exactly where heat pumps work best. Here’s how the pairing works, what to plan for in an Ontario winter, and the rebates available right now.
The short version
- A heat pump is more efficient when it only has to make warm water, and radiant floors are one of the best matches for that1.
- Air-to-water and ground-source heat pumps can feed a radiant floor directly. Air-to-air units heat the air, and pair with radiant for summer cooling.
- An air-source heat pump loses capacity in the coldest weather1, so the design sizes it from a heat-loss calculation and plans backup heat for the coldest days.
- Ontario’s Home Renovation Savings program has heat pump rebates, with pre-approval required2. The federal Greener Homes grant and loan are closed to new applicants3, 4.
01 · The physics
Why radiant floors and heat pumps pair so well
A heat pump doesn’t burn anything. It moves heat from the outdoor air or the ground into your home, and the less it has to raise the temperature, the more heat it delivers for the electricity it uses1. Asking it for hot water to feed old radiators pushes it toward the inefficient end of its range. Asking it for warm water to feed a floor keeps it at the good end.
That’s why radiant floors are one of the most future-proof ways to heat a home. The whole floor acts as one large, gentle radiator, so it can keep a room comfortable on water that’s only warm, which is exactly what air-to-water heat pumps produce most efficiently. Natural Resources Canada notes they run more efficiently heating water below about 45 to 50 °C, which makes them a better match for radiant floors or fan coils1.
Relative water temperature each system is typically designed for. An illustration, not measured data.
02 · The options
Three kinds of heat pump, and how each fits radiant
Warm water from outdoor air
An outdoor unit heats water for the floor loops. Its capacity drops as the weather gets colder, so the design matches it to your heat loss and plans for the coldest days.1
Heat from the ground
Loops buried in the yard or in drilled boreholes bring the ground’s warmer, more stable temperature to a water-to-water unit indoors that heats water for the floor. Steadier in deep cold, with a bigger job outside.1
Heats and cools the air
Ducted or ductless. It doesn’t feed a floor, but it pairs well with one: the floor heats, and the heat pump handles summer cooling.
03 · Ontario winters
Designing a heat-pump radiant system for Ontario
A heat pump rewards good design even more than a boiler does, because its efficiency and its output both depend on the water temperature you ask it for.
04 · Rebates in 2026
Ontario heat pump rebates in 2026
Ontario’s main program is Home Renovation Savings, delivered by Save on Energy and Enbridge Gas with support from the Ontario government5. A heat pump is a single upgrade, so it doesn’t need a home energy assessment first. The rebate depends on the size of the heat pump and on how you heat your home now2.
A few rules decide whether you actually get the money:
- Pre-approval comes first. Installations done before approval aren’t eligible2.
- You work through a participating HVAC contractor, who helps choose the unit and submits the pre-installation application2.
- The exact model has to be on the qualified list. Cold-climate air-source and water-to-air ground-source units must be on Natural Resources Canada’s list, and water-to-water ground-source units on the ENERGY STAR geothermal list2. For radiant, check the specific air-to-water unit before you count on a rebate.
- Insulation, air sealing, windows and doors are in the same program. Those go through a registered energy advisor’s assessment before and after the work, with $600 back to offset the assessments6, and attic insulation is also offered as a single upgrade5. Lower heat loss means a smaller heat pump, so they’re worth a look before you size one.
- Income-qualified households have had separate offers through Save on Energy, including free cold-climate heat pumps for electrically heated homes7 and no-cost installation for oil-heated homes through the federal Oil to Heat Pump Affordability program8. Check Save on Energy for what’s open now.
05 · Heat pump questions
Radiant and heat pump questions
Can my existing radiant floor run on a heat pump?
Often, but it depends on the water temperature the floor was designed for. A heat-loss calculation and a look at the loop spacing tell us whether your rooms will stay comfortable at heat-pump water temperatures, or what would need to change.
Do I still need a boiler?
Not always. An air-source heat pump has less capacity on the coldest days, and Natural Resources Canada recommends considering a supplementary heat source1. The heat-loss calculation sets the load on the coldest day, and that decides how much backup you’d want.
Can a heat pump cool through the floor?
Radiant floors are for heating. For summer cooling, many homes pair radiant floors with a small ducted or ductless system, and we coordinate with your other trades so everything works together.
Is an air-to-water heat pump eligible for the Ontario rebate?
It depends on the model. Check that the exact unit is on the qualified list the program uses, and get pre-approval before anything is installed.
Should I put in radiant now and a heat pump later?
That’s a solid plan. Design the floor for low water temperatures from the start, run it on a condensing boiler today, and it’s ready for a heat pump when you are.
Sources
- Natural Resources Canada, Heating and cooling with a heat pump.
- Home Renovation Savings, Heat pumps (no energy assessment required).
- Natural Resources Canada, Closed: Canada Greener Homes Grant.
- CMHC, Canada Greener Homes Loan.
- Save on Energy, Home Renovation Savings Program.
- Home Renovation Savings, Energy assessment required upgrades.
- IESO, Free Cold Climate Air Source Heat Pumps for Income-Eligible Ontario Residents (Dec 2023).
- Natural Resources Canada, Making Home Heating More Affordable for Ontarians (Sep 2025).
Sources checked September 2026. Programs, amounts and codes change, so confirm current details with the source before you plan around them.
Keep reading
More radiant guides
- Guide
What drives radiant floor heating cost
What moves the number, and what a good quote includes.
- Guide
Heat-loss calculations, explained
What goes into one, and why every radiant system is sized from it.
- Service
Radiant heating design
Room-by-room heat loss, loop layouts and water temperatures, heat-pump ready.
Your project next
Plan it heat-pump ready
Book a free consultation and we’ll walk your home or your plans, run the heat-loss numbers, and design radiant around the water temperatures a heat pump needs. No pressure, no guesswork.
