Gas furnaces typically run better than oil burners in terms of operational difficulties and they also burn cleaner because of the type of fuel used – natural gas and propane. In fact, the problems that affect gas furnaces typically involve the furnace’s thermocouple, the pilot light, or some component of the electrical system.
Leaks are rare, but no furnace is 100% fail safe, regardless of the redundancies and shutoffs included in the unit. If you smell gas in your house, do not turn any lights on or off and do not try to shut off the gas leading to the furnace. Get out of the house, leaving the door open and immediately call the gas company and the fire department to report the leak. Do not re-enter your home until authorities arrive, assess the situation, and give you word that it’s safe to do so.
Gas furnaces require a pilot light. Sometimes they are covered by a plug-type door and, on other units, an access panel. The pilot light controls, reset buttons, gas valves, and thermocouple are all together in an assembly at the front of the furnace. The furnace limit switch is located on the main chamber or main duct junction on the upper housing of the furnace.
It is not terribly hard to blow out the pilot light. The pilot light on a gas furnace can be extinguished due to drafts. To relight the pilot, follow the manufacturer’s instructions; they’re usually fastened to the furnace. If instructions for relighting the pilot are not provided, follow this general procedure:
Find the assembly – look for a valve with On, Off, and Pilot marked on it. Turn the valve to the Off position and wait approximately three minutes. Switch the valve to the Pilot setting. Hold a lighted match to the pilot opening while you push the reset button on the pilot control panel. Keep this button depressed until the pilot flame burns brightly, then set the valve to the On position. If the pilot flame won’t stay lit, the opening may be clogged. Turn the gas valve Off and clean the opening with piece of fine wire. If it won’t stay lit after several attempts, you may have a faulty thermocouple. If the pilot flame still won’t stay lit, call a professional service technician.
Not all furnaces use a pilot light. Some have an electrical system that ignites the gas instead of using flame. In these systems, the electric element heats up and ignites the burners. If this electrical ignition system malfunctions, call Mckinnon for repairs right away.