This type of furnace is fueled by liquid propane gas, which is burned to push hot air through your home. A pilot light ignites the burners within a combustion chamber, which push heat into the heat exchanger and eventually through your entire home. Repairing this type of furnace can be more expensive than its electric alternative. For example here are some common propane gas repairs and their costs:
Wife and I bought a fixer-upper last year. One of the issues it had was a lack of heating for the house. I called Affordable Furnace Repair and they sent Don out. He checked on the furnace and found one of the heating elements had gone bad. He fixed it quickly and we had a warm winter. Plus we got a box of filters for cheap from him, all around good service.
Heat exchangers are the components that draw heat from the burned gas. To draw more heat from the air they burn, energy-efficient furnaces supplement the primary exchanger with a second exchanger. Because the exhaust gases in that second exchanger might yield a corrosive acidic condensate, the second exchanger is made of stainless steel, lined with plastic, or otherwise protected.
Gerardo was very professional and kept us informed of what he was doing and what was needed. Our house is now the warmest it has been since we purchased it 3 years ago! And all of this was done on a Saturday morning with below freezing temps! We are very thankful and will be using Gerardo of True Comfort again when have the money to replace the furnace altogether.