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

December 06, 2019

While your Lennox® heating system can’t speak to you, it does have a way to communicate a furnace error.

Its control panel has two LED lights that can share a fault code. Based on the problem, your heating system may use continuous or flashing lights.

While there are various basic HVAC repairs you can take care of yourself, many fixes are best left to HVAC technicians. When your heater won’t turn on or give heated air, get in touch with Halverson Brothers Inc at 715-352-4052 for expert furnace repair in Menomonie and western Wisconsin.

Our technicians will speedily diagnose and repair the fault, even if you don’t have a Lennox heater. We can service whichever types or models—and get the warmth restored to your house fast.


What Does the Blinking Light on My Heater Mean?

Your furnace depends on lights to flash code when it requires repairs. It also uses these lights to tell you it’s working properly.

Normal heating consists of:

  • Concurrent slow flash—furnace working like it should.
  • Concurrent fast flash—furnace is initiating the call for heat.

If you realize that one light blinking slowly and the other flashing quickly, your heating system might have a low flame signal. This can take place even when your heater is working like it should. It signifies the flame sensing rod might have build-up or in the bad location on the burner. Reach out to us at 715-352-4052 for support.

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

Heater Won’t Turn On

Here are some of the light sequences you could notice when your heater refuses to or keep operating. The bulk of these problems must be handled by an expert, like one from Halverson Brothers Inc.

  1. All LED lights aren’t lit. This means your furnace might not have power. Examine the breaker box to make sure the heater fuse hasn’t flipped. You should reset the fuse if it’s in the “off” position. If it instantly turns off after you reset it, don’t try to reset it again and get in touch with us us at 715-352-4052.
  2. An individual light is solid and the other is flickering slowly. This shows the flame rollout switch is possibly open. The component is a critical safety device that helps in stopping fires and carbon monoxide. You shouldn’t seek to handle this problem on your own.
  3. An individual light is flashing rapidly and the other is blinking slowly. This usually indicates power polarity has been transposed. Your heater could have a wiring problem that calls for professional aid from Halverson Brothers Inc.
  4. The pair of lights are flickering slowly. This signifies your heating system’s blower motor possibly isn’t running. This component circulates warm air from the furnace into your space. We can assist in pinpointing what’s causing an issue with this component.
  5. An individual light is blinking slowly and the other is flickering fast. This indicates your furnace could have insufficient voltage or a short circuit. Contact our specialists at 715-352-4052 for support.
  6. One light is flashing on, on and off while the other flashes on, off, on. This indicates there could be trouble with your heater’s control board or wiring. Halverson Brothers Inc can determine the error and fix it.
  7. The pair of lights are using alternating slow flickers. This means your heating system may have a flame problem. There could be trouble with its gas supply, gas valve or ignitor control. Reach out to us at 715-352-4052 for help.
  8. One light flickers slowly while the other is continuous. This often indicates your HVAC equipment’s limit switch is experiencing an error. The switch prevents your heater from becoming too warm. Call the experts at Halverson Brothers Inc for assistance.

Heater Blower Runs But No Heat

Here’s what could be at fault when you observe your heating equipment’s blower fan on, but you aren’t receiving any warm air.

  • The pair of lights are showing every other fast flashes. This indicates your furnace ignitor may be broken. This piece lights energy in your HVAC equipment to produce warm air and should be serviced by an expert from Halverson Brothers Inc.

Depend on Us for Professional Furnace Repair

When you have to get your heater in working order without delay, depend on the experts at Halverson Brothers Inc. Our techs will handle the fault right away and have your residence feeling comfortable again soon. Contact us at 715-352-4052 or contact us online to get an appointment now.