I get those letters in the mail telling me that I use 90 percent more power than my neighbors with electric heat. I don't have electric heat and my normal bill is 120ish a month. They lie. Anyone heating with only electric heat is paying 500 a month plus for electric. I bet my water heater is half my bill and the dry is a quarter of it. Family of 4 uses a lot of hot water and does a lot of laundry. Those taco pumps draw next to nothing for power and a furnace blower won't kill the bill. You shouldn't need aux heat with a OWB. Any sort of boiler is great once it's hot it shouldn't run much to maintain that heat. I believe a boiler with a water coil is the best way to heat.