There are air-to-water heat pumps, provided your emitters are sized such that you can heat your home with flow temps at/under 135°F. (I was able to test the pri

There are air-to-water heat pumps, provided your emitters are sized such that you can heat your home with flow temps at/under 135°F. (I was able to test the prior winter and turning my aquastat way down and see when the house was no longer able to maintain the desired setpoint. For me, that was at about 9°F and it fell by about 1°F inside for every 2°F outside below that over a single night.) If you can get by with 135°F (or ideally 130°F) flow, Google for "air to water heat pump" and there's likely a vendor that will sell into Ontario. (Ultimately, I decided against it for economic reasons, mostly because of a monopoly supplier in my area giving me a monopoly quote while not accepting Monopoly money.)