Our furnace has quit and a major decision has to be made. We have a gas (propane) furnace that has lasted 15 years. The outside cooling unit would still work IF the furnace fan system was working. The furnace people have recommended Carrier. They also carry Trane. Does anybody have recent experience with the duel system with gas and heat pump? This will be a major expense, more than 15,000.00 so anybody with knowledge to help guide me to the best decision of a bad deal would be appreciated.