You don't have many options. I think everything is cheaper than Propane, unless your electric is very high. Kerosone is not cheap either. Heat pump is the most efficient there is since in theory it can put out more heat energy than the electric energy it uses. Not perpetual motion, it is just borrowing the heat from somewhere else. So you are already half way there. I think you should look into ground source heat pump if you have a little land for it. As far as the system you have you could turn the temp down and get a couple of space heaters for certain rooms. Works good unless you have a wife then its no good... You could get an energy audit and you might find ways to improve your energy effeciency.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra