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

December 06, 2019

While your Lennox® heater can’t speak to you, it does have 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. Based on the malfunction, your heater could use solid or flashing lights.

Though there are certain simple heating fixes you can take care of on your own, most fixes are best left to the professionals. When your furnace refuses to turn on or provide heated air, get in touch with Keystone Heating & Air Conditioning Co., Inc at 262-358-9468 for expert furnace repair in Racine.

Our technicians will rapidly diagnose and fix the breakdown, even if you don’t own a Lennox heater. We can fix whichever kinds or models—and get the heat restored to your residence fast.


What Does the Flashing Light on My Heating System Mean?

Your furnace relies on lights to flash code when it needs to be repaired. It also works this setup to relay it’s operating like it should.

Regular heating includes:

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

If you notice a lone light blinking slowly and the other blinking fast, your furnace could have a low flame signal. This can happen even when your heater is operating like it should. It means the flame sensing rod may need to be cleaned or in the wrong location on the burner. Call us at 262-358-9468 for assistance.

Here are some of the most routine faults for Lennox heating systems.

Furnace Won’t Start

Here are many of the light sequences you could observe when your heating system won’t turn on or keep heating. The majority of these errors have to be taken care of by a specialist, like one from Keystone Heating & Air Conditioning Co., Inc.

  1. All LED lights aren’t lit. This means your heater might not be receiving power. Examine the breaker box to ensure the heater fuse hasn’t triggered. Try resetting the fuse if it is in the “off” spot. If it promptly turns off following a reset, don’t touch the breaker and call us at 262-358-9468.
  2. An individual light is solid and the other is flickering slowly. This implies the flame rollout switch is may be open. The component is a critical safety tool that helps in stopping fires and carbon monoxide. You shouldn’t try to handle this problem yourself.
  3. One light is blinking quickly and the other is flashing slowly. This usually means power polarity has been reversed. Your furnace might have a wiring error that needs specialized assistance from Keystone Heating & Air Conditioning Co., Inc.
  4. Both lights are flashing slowly. This means your heater’s blower motor possibly isn’t working. This piece circulates heated air from the furnace into your space. We can help in pinpointing what’s causing a problem with this part.
  5. One light is blinking slowly and the other is flashing quickly. This signifies your heater may have low voltage or a short circuit. Contact our technicians at 262-358-9468 for help.
  6. One light is flashing on, on and off while the other blinks on, off, on. This means there may be a problem with your heater’s motherboard or wiring. Keystone Heating & Air Conditioning Co., Inc can pinpoint the issue and handle it.
  7. The pair of lights are using alternate slow flickers. This signifies your HVAC system possibly has a flame error. There may be a problem with its gas supply, gas valve or ignitor control. Reach out to us at 262-358-9468 for support.
  8. One light flashes slowly while the other remains steady. This typically means your HVAC equipment’s limit switch is not working. The switch keeps your HVAC system from overheating. Contact the professionals at Keystone Heating & Air Conditioning Co., Inc for assistance.

Heater Blower Operates But No Heat

Here’s what might be broken when you observe your furnace’s blower fan working, but you aren’t getting any warm air.

  • The duo of lights are giving alternating quick flickers. This means your furnace ignitor might not be working. This piece lights energy in your heater to produce warm air and should be serviced by a specialist from Keystone Heating & Air Conditioning Co., Inc.

Trust Us for Professional Furnace Repair

When you need to get your heater in working order fast, trust the professionals at Keystone Heating & Air Conditioning Co., Inc. Our pros will take care of the error without delay and have your house feeling comfortable again in no time. Reach out to us at 262-358-9468 or contact us online to request an appointment today.