Patent ID: 7398778

Claim:
An electric forced-air hydronic furnace for heating water for an on-demand hot water system and heating a recirculating air flow in a continuous air duct system, a cold water supply and a hot water outlet, said furnace comprising: a. a housing, b. an electric flash heater for heating water from said cold water supply to provide said on-demand hot water, c. a split heat pump having an evaporator component thereof located external of said housing and a condenser component thereof that emits heat located within said housing, d. a first heat exchanger within said housing that includes said condenser component as the heat source to heat said recirculating air flow when said heat pump is activated and said condenser component emits heat, e. a second heat exchanger within said housing that receives heated air from said first heat exchanger and includes a hydronic heat exchanger coil through which flows selectively either (i) water from said cold water supply to be heated by heat from said heated air and used for said on-demand hot water, or (ii) hot water from said flash heater to provide supplemental heat to said air flow across said second heat exchanger, f. a blower for forcing said recirculating air flow through said first and second heat exchangers, through said continuous air duct system and back to said first heat exchanger, and g. a control means for operating said furnace for heating and delivering said on-demand hot water and/or for heating said recirculating air.