Furnace troubleshooting

Top Lennox® Furnace Error Codes (and What They Mean)

While your Lennox® furnace isn’t able to speak to you, it has a process to get your attention when there’s a furnace error.

Its control board has two LED lights that can share a fault code. Depending on the failure, your furnace could display continuous or flashing lights.

Though there are some simple HVAC fixes you can do yourself, many tasks are best left to experts. When your furnace won’t kick on or provide warmth, call Thurston Heating & Air Conditioning at 308-624-3485 for professional furnace repair in Kearney.

Our technicians will swiftly identify and fix the fault, even if you don’t use a Lennox heater. We can service any kinds or models—and get the comfort reintroduced to your house quickly.


What Does the Flickering Light on My Furnace Mean?

Your heater relies on lights to flash code when it isn’t working right. It also works this setup to tell you it’s running correctly.

Regular heating includes:

  • Concurrent slow flash—heating system working properly.
  • Concurrent fast flash—heater is initiating the call for heat.

If you realize that a single light blinking slowly and the other flashing rapidly, your furnace might be experiencing a low flame signal. This can occur even when your heater is heating like it should. It signifies the flame sensing rod might need to be cleaned or in the bad location on the burner. Contact us at 308-624-3485 for help.

Here are several other of the most routine faults for Lennox furnaces.

Heater Refuses to Turn On

Here are some of the light sequences you might notice when your furnace won’t turn on or stay on. The bulk of these problems have to be repaired by a professional, for instance from Thurston Heating & Air Conditioning.

  1. All LED lights are off. This signifies your heater might not have electricity. Examine the breaker box to ensure the furnace fuse has not tripped. Try resetting the fuse if it is in the “off” position. If it rapidly flips following a reset, don’t touch the breaker and get in touch with us us at 308-624-3485.
  2. An individual light is unchanging and the other is blinking slowly. This shows the flame rollout switch is likely not working right. The component is an essential safety device that assists in avoiding fires and carbon monoxide. You shouldn’t attempt to fix this problem on your own.
  3. One light is flickering rapidly and the other is flashing slowly. This usually indicates power polarity has been inverted. Your furnace could have a wiring fault that needs specialized assistance from Thurston Heating & Air Conditioning.
  4. Both lights are blinking slowly. This means your heater’s blower motor likely isn’t running. This part moves warm air from the HVAC system into your residence. We can assist in pinpointing what’s wrong with this component.
  5. A single light is flashing slowly and the other is flashing fast. This means your heating system might have insufficient voltage or a short circuit. Reach out to our specialists at 308-624-3485 for support.
  6. One light is flickering on, on and off while the other blinks on, off, on. This indicates there could be trouble with your furnace’s control board or wiring. Thurston Heating & Air Conditioning can pinpoint the fault and take care of it.
  7. The duo of lights are using every other slow flickers. This signifies your heater likely has a flame failure. There may be an issue with its gas supply, gas valve or ignitor control. Call us at 308-624-3485 for assistance.
  8. An individual light flashes slowly while the other remains steady. This often indicates your HVAC system’s limit switch is not working. The switch keeps your heating system from overheating. Reach out to the professionals at Thurston Heating & Air Conditioning for assistance.

Heater Blower Runs But No Heat

Here’s what may be wrong when you notice your heating system’s blower fan working, but you aren’t gaining any warmth.

  • The duo of lights display alternating fast flashes. This means your furnace ignitor might not be in working order. This component kindles fuel in your HVAC equipment to create warm air and should be repaired by a specialist from Thurston Heating & Air Conditioning.

Trust Us for Skilled Furnace Repair

When you need to have your furnace in working order fast, depend on the specialists at Thurston Heating & Air Conditioning. Our technicians will fix the fault without delay and have your residence feeling relaxing again in a short time. Get in touch with us at 308-624-3485 or contact us online to request an appointment now.

Back To Blog