The components inside a central air conditioner are more complex than many homeowners realize. HVAC technicians must be able to diagnose and repair a variety of mechanical issues that can arise in these appliances. Here is an introduction to three furnace heating problems that you may encounter.
1. Dirty Furnace Burners
The burner is the component that ignites gas and air inside your furnace to produce heat. Unfortunately, soot and other combustion byproducts can cover and clog your furnace burners over time.
Clean burners will produce a steady blue flame. Your burners may need to be cleaned if your furnace pilot light is yellow and flickering. Dirty burners also tend to reduce the total heat output of a furnace, so take notice if your furnace hasn't been performing as well as it should recently.
An HVAC contractor can resolve issues from a dirty furnace burner by removing the burner and cleaning it. If you schedule regular furnace maintenance, your technician will inspect the burner during each visit and clean it as needed.
2. Limit Switch Failure
The limit switch is an essential safety component in every modern furnace. This device detects the ambient temperature inside your furnace and deactivates the appliance in the event of overheating.
Furnace limit switches can fail due to electrical shorts or a buildup of soot and grime. When your limit switch is going bad, you may notice that your furnace blower doesn't shut off when it's done heating, even in "auto" mode. Limit switches are modular components that your HVAC contractor can replace during a service call.
3. Poor Blower Motor Lubrication
The blower motor inside your furnace turns the blower fan to circulate warm air through your home. The bearings in the blower motor must remain lubricated to prevent excess buildup of heat. Adding oil to the blower motor is sometimes needed during regular heating maintenance.
Lubricating a furnace blower motor is a complex job. Your technician may need to remove the blower motor from your furnace to access the oil ports on the side of the motor.
Some newer furnaces contain direct-drive blower motors, which are an exception to this requirement. Direct-drive motors have sealed bearings that should never need added oil.
The complexity of furnace repair highlights the importance of regular professional maintenance. If your furnace is underperforming, leave repairs to a professional and call a professiona heating contractor in your area.