There are air-to-water heat pumps that can run hydronic heating (even radiators, though underfloor is a better match due to the lower return temps).
You can then make your own hybrid with a resistive electric boiler or a gas boiler wired to second-stage or emergency heat.
My 1920s house with radiators and terrible insulation outside of Boston runs with return water temps in the low 90s in shoulder season and 120°F when it’s 12°F outside, using outdoor-reset/weather-compensation.
Those return temps are entirely compatible with air-to-water heat pumps. (And result in 22-24 hour run times per day, which makes for extremely comfortable heat, despite the generally lacking insulation.)
I don’t have one because HVAC contractors are living in the 1990s and want to do a 3-hour, 2-person combi boiler install for $10K in profit rather than think through how to do anything unusual.
You can then make your own hybrid with a resistive electric boiler or a gas boiler wired to second-stage or emergency heat.
My 1920s house with radiators and terrible insulation outside of Boston runs with return water temps in the low 90s in shoulder season and 120°F when it’s 12°F outside, using outdoor-reset/weather-compensation.
Those return temps are entirely compatible with air-to-water heat pumps. (And result in 22-24 hour run times per day, which makes for extremely comfortable heat, despite the generally lacking insulation.)
I don’t have one because HVAC contractors are living in the 1990s and want to do a 3-hour, 2-person combi boiler install for $10K in profit rather than think through how to do anything unusual.