Unfortunately it is probably not possible to hook our heat pump to your existing radiators in lieu of your existing boiler. Our heat pumps produce approx.. 115F supply temp for home heating. Typically baseboard heaters run hotter than that, 180F is a common temperature with these. For our customers who have baseboard heaters/radiators and would like to reduce their heating costs, we would have two options.
The first would be to replace the baseboard heaters with newer hydronic fan coil systems that are designed to produce high BTU with low supply temperature.
The second would be to look at installing a retrofit forced air system, we offer a terrific system that uses 2” branch ducting so it is very easy to install into a previously radiator heated home.