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

December 06, 2019

While your Lennox® heating system cannot talk to you, it does have a way to get your attention when there’s a furnace error.

Its control board has double LED lights that can show a fault code. Subject to the problem, your heater may display steady or flashing lights.

Although there are certain elementary HVAC fixes you can finish on your own, most tasks are best left to experts. When your heater will not turn on or give heat, get in touch with Forster Heating at 530-885-8081 for professional furnace repair in Auburn.

Our specialists will swiftly detect and repair the malfunction, even if you don’t have a Lennox furnace. We can repair any kinds or makes—and get the comfort reintroduced to your residence quickly.


What Does the Blinking Light on My Furnace Mean?

Your heater uses lights to flash code when it needs to be repaired. It also uses these lights to tell you it’s working properly.

Regular heating includes:

  • Concurrent slow flash—heating system heating properly.
  • Simultaneous fast flash—heating system is beginning to call for heat.

If you notice a solitary light flashing slowly and the other flashing quickly, your heating system may be having a low flame signal. This can take place even when your heater is heating like it should. It means the flame sensing rod could have build-up or in the incorrect spot on the burner. Call us at 530-885-8081 for support.

Here are some of the most typical errors for Lennox HVAC systems.

Heater Won’t Kick On

Here are a few of the light sequences you may observe when your furnace refuses to or stay on. Most of these errors have to be fixed by an expert, like one from Forster Heating.

  1. All LED lights aren’t lit. This means your furnace might not have electricity. Check the breaker box to ensure the heating system fuse hasn’t flipped. Attempt to reset the fuse if it’s in the “off” position. If it instantly trips after a subsequent reset, leave the breaker alone and get in touch with us us at 530-885-8081.
  2. A single light is stable and the other is flickering slowly. This signifies the flame rollout switch is possibly malfunctioning. The component is a critical safety mechanism that aids in stopping fires and carbon monoxide. You shouldn’t seek to take care of this fault without professional help.
  3. A single light is flashing rapidly and the other is blinking slowly. This often means power polarity has been reversed. Your heater could have a wiring problem that calls for expert help from Forster Heating.
  4. Both lights are flashing slowly. This signifies your heater’s blower motor possibly isn’t working. This part circulates hot air from the HVAC system into your rooms. We can assist in pinpointing what’s causing a problem with this component.
  5. A single light is flashing slowly and the other is flickering fast. This means your heater may have insufficient voltage or a short circuit. Call our technicians at 530-885-8081 for help.
  6. One light is blinking on, on and off while the other flashes on, off, on. This signifies there might be a malfunction with your HVAC system’s motherboard or wiring. Forster Heating can find the problem and repair it.
  7. The pair of lights display alternating slow flashes. This indicates your HVAC system likely has a flame issue. There could be an issue with its gas supply, gas valve or ignitor control. Call us at 530-885-8081 for assistance.
  8. One light blinks slowly while the other stays continuous. This often indicates your furnace’s limit switch is not working. The switch keeps your heater from overheating. Get in touch with the experts at Forster Heating for help.

Heating System Blower Operates But No Warm Air

Here’s what might be broken when you hear your heater’s blower fan running, but you aren’t gaining any warm air.

  • Both lights display alternate rapid blinks. This signifies your furnace ignitor might not be in working order. This component ignites gas in your heating system to create warmth and should be fixed by an expert from Forster Heating.

Depend on Us for Expert Furnace Repair

When you have to have your furnace in working order quickly, depend on the experts at Forster Heating. Our pros will repair the fault quickly and have your home feeling cozy again in a short time. Get in touch with us at 530-885-8081 or contact us online to get an appointment today.