Retrofit Residential Boilers with Hydronic Heat Pumps

If your house heats with a gas boiler and radiators, baseboards, or radiant floors, a newer option lets you switch to electric heat without tearing out that existing plumbing. Called an air-to-water heat pump, or hydronic heat pump, it pulls heat from outdoor air and sends it through the same hot-water pipes and radiators you already have. In milder climates it can fully replace the boiler; in colder regions, homeowners often keep the old boiler or electric resistance heat as backup for the coldest days or when the system needs hotter water than the heat pump can supply. Unlike a standard boiler, these systems can also run in reverse to provide cooling, so one setup handles both heating and cooling.

One thing to know: old boilers can heat water up to 180°F, while many hydronic heat pumps top out around 140°F. That difference matters for how well your existing radiators or floor heat perform, which is why a combined heat-pump-plus-backup-boiler setup is common in colder climates or older systems built for higher temperatures.

These systems tend to cost more upfront than a standard boiler swap, but can lower your operating costs over time, particularly if they also handle your hot water. Federal incentives for this kind of upgrade have shifted, but state, local, and utility rebate programs still exist in many places, especially where hydronic heating is common — worth checking what's available where you live.