You always expect your furnace to deliver the warmth you want throughout your home, which makes getting lukewarm or ice-cold air an unpleasant surprise. When your furnace decides to go cold on you, you'll want to know the underlying cause. Here are a few to consider until a technician arrives on the scene to thoroughly diagnose and pinpoint the problem.
No Ignition, No Heat
The ignition system is the heart and soul of your furnace. Without ignition, you won't get the flames that produce the heat your furnace distributes throughout your living spaces. Instead of using outdated pilot lights that remain on as long as the furnace has fuel, modern furnaces rely on electronic ignitors to kick start the gas burners.
If the electronic ignitor stops working due to defect or wear, you won't get any heat from your furnace. If the burners are clogged and unable to properly pass fuel, however, the ignitor can't start the furnace due to inadequate fuel flow.
Every furnace is equipped with failsafes that protect your furnace and your home from serious damage. If your furnace runs into an unusual problem upon startup or during operation, these controls will activate and, in most cases, shut down the furnace until the problem is corrected. The following gives you an idea of what some of these failsafes do when your furnace runs into trouble:
- The limit switch protects the heat exchanger and other parts of the furnace from overheating.
- The air pressure switch stops the furnace if exhaust gases aren't venting properly.
- The flame sensor shuts off fuel flow if it fails to detect the presence of a flame during furnace operation.
If your furnace suddenly shuts down due to any of the above, don't attempt to restart it. Instead, call an HVAC specialist and have the technician perform a thorough inspection.
Electrical Troubles Ahead
Unlike more mechanical heating systems like boilers, the typical furnace relies heavily on electronics for its operation. An electrical problem can easily sideline your furnace until your HVAC specialist or electrician can properly diagnose and repair the problem. Here are a few electrical issues that could put a damper on your home comfort:
- Blower fan motor failure
- Improperly wired thermostat
- Damaged or defective control board or thermostat circuitry
- Electrical supply issues
Fortunately, annual inspections and regularly scheduled maintenance can help keep these and other furnace issues a rarity. If you're having electrical troubles with your furnace, don't attempt to fix the problem yourself. DIY repairs always carry an electrocution risk, especially when dealing with furnace components capable of delivering high voltage. Call for local heating repair service for more information.