I have a radiant floor installed which uses a propane fired tankless water heater to heat the water. It is too expensive for us to operate and I want to change the way I heat the water. Can I simply install a small boiler in the basement and change the hot water supply line for the radiant floor from the old tankless heater to the new boiler output? It seems like it should work. I can get all the free wood I can use so a small boiler would costs almost nothing to operate. Are there smaller, less expensive, boilers made just for this application? Thanks for any ideas.