The heat exchanger is the core furnace part that ... $4,745 to replace an electric furnace and about $7,235 to replace a gas furnace. At an average cost of $270 per visit, furnace repair is ...

Derived from the Latin word fornax, meaning oven, a furnace ... gas from building up dangerously if the igniter fails, flame detectors shut off gas flow if no heat is detected. Heat exchanger ...