I am moving into a house with oil-fired baseboard heating, and no central a/c. The boiler is on its last legs and will need to be replaced shortly (likely within a couple of years). I would like to replace the baseboard heating with radiant floor heating. I would like an alternative fuel other than oil, however, natural gas is not available in the area. I have access to install the radiant tubing from below for the first floor; however, I would like to avoid ripping up the finishes on the 2nd floor for the time being. I am wondering if I can install radiant heating on the first floor, and keep baseboard heat on the 2nd floor until I am ready to rip up the 2nd floor finish floor to install a sub-floor with grooves and metal panels for radiant tubes. I feel I could accomplish this if I simply replaced the boiler; however, I would like to utilize (potentially) a geothermal heat pump and/or solar hot water. I believe these methods would generate a high enough water temperature for radiant heat, but not for baseboard heating. What are my options? Is there a supplemental heat source that could heat the water from 115 to 160 cost effectively? I would appreciate any thoughts or recommendations. Thank you!