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

December 06, 2019

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

Its motherboard has double LED lights that can show a fault code. Depending on the malfunction, your heating system may show continuous or flashing lights.

Although there are a few simple HVAC adjustments you can finish without an expert, many tasks are best taken care of by experts. When your furnace will not start or give heated air, contact Colvin's Heating and Cooling at 816-379-3918 for professional furnace repair in Excelsior Springs.

Our specialists will quickly diagnose and fix the issue, even if you don’t have a Lennox heater. We can repair whichever brands or models—and get the warmth returned to your residence quickly.


What Does the Blinking Light on My Heater Mean?

Your heater depends on lights to flash code when it needs to be repaired. It also engages this system to tell you it’s running correctly.

Normal operation involves:

  • Concurrent slow flash—heater running correctly.
  • Both lights flash fast—furnace is initiating the call for heat.

If you see a lone light blinking slowly and the other going on and off fast, your furnace may be having a low flame signal. This can take place even when your heater is working properly. It indicates the flame sensing rod may be dirty or in the wrong location on the burner. Call us at 816-379-3918 for support.

Here are a few other of the most typical problems for Lennox HVAC systems.

Heater Refuses to Kick On

Here are a few of the light patterns you could observe when your heat will not or keep operating. Most of these issues must be fixed by a professional, such as one from Colvin's Heating and Cooling.

  1. The duo of LED lights are off. This means your furnace might not be receiving power. Look at the breaker box to confirm the heater fuse has not tripped. Attempt to reset the fuse if it’s in the “off” position. If it instantly turns off after you reset it, leave the breaker alone and contact us at 816-379-3918.
  2. An individual light is solid and the other is flickering slowly. This shows the flame rollout switch is likely open. The switch is an essential safety guard that aids in stopping fires and carbon monoxide. You shouldn’t attempt to fix this issue on your own.
  3. An individual light is blinking quickly and the other is flickering slowly. This typically signifies power polarity has been inverted. Your heater may have a wiring fault that needs expert help from Colvin's Heating and Cooling.
  4. The pair of lights are flickering slowly. This signifies your heater’s blower motor possibly isn’t running. This component moves heated air from the heating system into your rooms. We can assist in determining what’s causing a problem with this piece.
  5. An individual light is blinking slowly and the other is blinking rapidly. This means your heater may have not enough voltage or a short circuit. Call our experts at 816-379-3918 for support.
  6. One light is flickering on, on and off while the other blinks on, off, on. This indicates there may be trouble with your HVAC system’s motherboard or wiring. Colvin's Heating and Cooling can determine the issue and fix it.
  7. Both lights show every other slow flashes. This signifies your heating system may have a flame issue. There might be a problem with its gas supply, gas valve or ignitor control. Contact us at 816-379-3918 for help.
  8. A single light blinks slowly while the other stays solid. This often signifies your heater’s limit switch is not working. The switch keeps your heating system from becoming too warm. Get in touch with the specialists at Colvin's Heating and Cooling for help.

Heating System Blower Runs But No Heat

Here’s what might be at fault when you notice your heater’s blower fan on, but you aren’t getting any heated air.

  • The pair of lights are showing alternating rapid flickers. This indicates your furnace ignitor might be broken. This component lights energy in your heater to create warm air and should be serviced by a technician from Colvin's Heating and Cooling.

Turn to Us for Expert Furnace Repair

When you need to get your heating system repaired without delay, turn to the experts at Colvin's Heating and Cooling. Our technicians will fix the issue quickly and have your rooms feeling relaxing again soon. Contact us at 816-379-3918 or contact us online to request an appointment today.