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

December 06, 2019

While your Lennox® HVAC equipment cannot chat with you, it possesses a method to get your attention when there’s a furnace error.

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

While there are some elementary heating repairs you can take care of yourself, the majority of services are best left to the professionals. When your heating system will not start or put out heated air, reach out to Home Comfort Heating & Air at 763-276-0617 for experienced furnace repair in Elk River.

Our specialists will rapidly discover and handle the fault, even if you don’t use a Lennox furnace. We can repair all types or configuration—and get the warmth reintroduced to your house fast.


What Does the Blinking Light on My Heater Mean?

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

Regular operation consists of:

  • Both lights flash slowly—furnace working like it should.
  • Concurrent fast flash—heating system is starting to call for heat.

If you realize that a solitary light flashing slowly and the other flashing quickly, your furnace could be having a low flame signal. This can take place even when your heater is operating properly. It indicates the flame sensing rod might have build-up or in the incorrect area on the burner. Contact us at 763-276-0617 for help.

Here are a few other of the most common issues for Lennox furnaces.

Heater Won’t Kick On

Here are many of the light arrangements you could observe when your heat will not or keep operating. The majority of these issues must be repaired by a specialist, like one from Home Comfort Heating & Air.

  1. Both LED lights aren’t lit. This indicates your heating system might not have power. Go to the breaker box to ensure the furnace fuse has not flipped. You should reset the fuse if it is in the “off” position. If it immediately turns off following a reset, leave the breaker alone and contact us at 763-276-0617.
  2. One light is unchanging and the other is flickering slowly. This shows the flame rollout switch is possibly open. The component is a critical safety guard that helps in preventing fires and carbon monoxide. You shouldn’t try to repair this problem on your own.
  3. A single light is flashing rapidly and the other is flashing slowly. This typically means power polarity has been transposed. Your heater may have a wiring error that calls for professional help from Home Comfort Heating & Air.
  4. Both lights are blinking slowly. This indicates your heating system’s blower motor probably isn’t operating. This part moves hot air from the furnace into your house. We can aid in figuring out what’s causing an issue with this component.
  5. A single light is flashing slowly and the other is flickering fast. This signifies your HVAC system could have insufficient voltage or a short circuit. Call our experts at 763-276-0617 for help.
  6. One light is flashing on, on and off while the other flashes on, off, on. This signifies there could be a problem with your furnace’s motherboard or wiring. Home Comfort Heating & Air can pinpoint the issue and handle it.
  7. Both lights show alternating slow blinks. This signifies your HVAC system likely has a flame failure. There may be a problem with its gas supply, gas valve or ignitor control. Call us at 763-276-0617 for help.
  8. A single light blinks slowly while the other stays solid. This often means your heating system’s limit switch is not working. The switch prevents your HVAC equipment from getting too hot. Call the experts at Home Comfort Heating & Air for assistance.

Heating System Blower Works But No Warmth

Here’s what could be wrong when you hear your furnace’s blower fan on, but you aren’t gaining any heated air.

  • The pair of lights display alternating rapid blinks. This indicates your furnace ignitor might not be working. This component kindles energy in your furnace to make warmth and should be serviced by a professional from Home Comfort Heating & Air.

Turn to Us for Expert Furnace Repair

When you need to have your heater repaired fast, turn to the experts at Home Comfort Heating & Air. Our pros will handle the issue promptly and have your house feeling relaxing again in no time. Reach out to us at 763-276-0617 or contact us online to schedule an appointment today.