Most Common Lennox® Furnace Error Codes (and What They Mean)

December 06, 2019

While your Lennox® heater isn’t able to chat with you, it has a process to communicate a furnace error.

Its control panel has a set of LED lights that can display a fault code. Depending on the malfunction, your heating system might show continuous or flashing lights.

While there are some basic HVAC adjustments you can finish on your own, the majority of repairs are best handled by HVAC technicians. When your heater will not start or give heat, call Bon Air Service Company at 972-332-1028 for skilled furnace repair in Grand Prairie.

Our specialists will rapidly diagnose and repair the problem, even if you don’t own a Lennox heating system. We can repair all types or makes—and get the heat returned to your residence quickly.


What Does the Flashing Light on My Heating System Mean?

Your heater depends on lights to flash code when it is malfunctioning. It also uses this setup to tell you it’s heating like it should.

Correct operation involves:

  • Both lights flash slowly—furnace working correctly.
  • Simultaneous fast flash—furnace is starting to call for heat.

If you realize that a lone light blinking slowly and the other going on and off quickly, your furnace may have a low flame signal. This can happen even when your heater is operating like it should. It signifies the flame sensing rod could have build-up or in the bad location on the burner. Reach out to us at 972-332-1028 for help.

Here are a few other of the most routine issues for Lennox heating systems.

Furnace Won’t Kick On

Here are a few of the light sequences you may notice when your heat will not or keep operating. Most of these issues need to be handled by a technician, for instance from Bon Air Service Company.

  1. The pair of LED lights are off. This indicates your HVAC system might not have electricity. Examine the breaker box to make sure the furnace fuse is not tripped. You should reset the fuse if it has moved into the “off” area. If it promptly turns off after a subsequent reset, leave the breaker alone and call us at 972-332-1028.
  2. A single light is stable and the other is blinking slowly. This shows the flame rollout switch is likely open. The component is a critical safety mechanism that helps in avoiding fires and carbon monoxide. You shouldn’t attempt to handle this malfunction without professional help.
  3. One light is blinking quickly and the other is flashing slowly. This usually means power polarity has been inverted. Your heating system could have a wiring fault that requires professional assistance from Bon Air Service Company.
  4. All lights are blinking slowly. This signifies your furnace’s blower motor likely isn’t running. This component circulates warm air from the heating system into your house. We can assist in determining what’s wrong with this component.
  5. An individual light is flickering slowly and the other is flickering fast. This signifies your heater may have low voltage or a short circuit. Contact our technicians at 972-332-1028 for assistance.
  6. One light is blinking on, on and off while the other blinks on, off, on. This signifies there could be a malfunction with your heater’s control panel or wiring. Bon Air Service Company can determine the issue and handle it.
  7. The duo of lights show alternating slow flickers. This signifies your HVAC system may have a flame error. There may be an issue with its gas supply, gas valve or ignitor control. Reach out to us at 972-332-1028 for assistance.
  8. An individual light flickers slowly while the other stays continuous. This typically indicates your HVAC equipment’s limit switch is malfunctioning. The switch keeps your heating system from overheating. Call the specialists at Bon Air Service Company for support.

Heater Blower Works But No Warm Air

Here’s what might be at fault when you observe your heating equipment’s blower fan on, but you aren’t gaining any warmth.

  • Both lights display alternate fast flickers. This indicates your furnace ignitor may not be working. This component ignites energy in your HVAC equipment to produce heat and should be fixed by a specialist from Bon Air Service Company.

Trust Us for Professional Furnace Repair

When you have to get your HVAC equipment repaired quickly, trust the technicians at Bon Air Service Company. Our pros will fix the issue quickly and have your rooms feeling relaxing again soon. Call us at 972-332-1028 or contact us online to schedule an appointment today.