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

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

Its motherboard has two LED lights that can display a fault code. Depending on the issue, your heater might use continuous or flashing lights.

Though there are a few simple HVAC repairs you can complete on your own, many tasks are best taken care of by experts. When your heating system will not kick on or put out warm air, reach out to Abilene Air-Tech Inc at 325-200-4667 for experienced furnace repair in Abilene.

Our specialists will speedily pinpoint and handle the fault, even if you don’t have a Lennox furnace. We can service any kinds or models—and get the heat reintroduced to your residence fast.


What Does the Flashing Light on My Heating System Mean?

Your heating system relies on lights to flash code when it needs to be repaired. It also engages these lights to relay it’s working correctly.

Correct operation consists of:

  • Both lights flash slowly—heater working correctly.
  • Simultaneous fast flash—heating system is beginning to call for heat.

If you see a single light flashing slowly and the other blinking rapidly, your furnace could be having a low flame signal. This can take place even when your heating system is running correctly. It means the flame sensing rod could be dirty or in the wrong spot on the burner. Contact us at 325-200-4667 for support.

Here are some of the most common errors for Lennox heaters.

Heater Will Not Turn On

Here are many of the light patterns you might observe when your heater refuses to or keep heating. The majority of these errors need to be repaired by an expert, for instance from Abilene Air-Tech Inc.

  1. All LED lights are extinguished. This indicates your heater might not be receiving power. Look at the breaker box to ensure the heater fuse has not triggered. You should reset the fuse if it has moved into the “off” spot. If it rapidly flips following a reset, don’t try to reset it again and get in touch with us us at 325-200-4667.
  2. An individual light is stable and the other is blinking slowly. This shows the flame rollout switch is possibly not working right. The component is a critical safety device that helps in stopping fires and carbon monoxide. You shouldn’t attempt to take care of this problem on your own.
  3. One light is flashing quickly and the other is blinking slowly. This usually means power polarity has been transposed. Your furnace might have a wiring issue that needs specialized help from Abilene Air-Tech Inc.
  4. All lights are blinking slowly. This means your heating system’s blower motor probably isn’t working. This component moves warm air from the heating system into your rooms. We can aid in determining what’s causing a problem with this piece.
  5. One light is flickering slowly and the other is flashing quickly. This means your heating system may have low voltage or a short circuit. Reach out to our specialists at 325-200-4667 for assistance.
  6. One light is flashing on, on and off while the other blinks on, off, on. This means there may be a fault with your furnace’s control board or wiring. Abilene Air-Tech Inc can find the problem and take care of it.
  7. The duo of lights are using alternate slow flickers. This signifies your HVAC equipment possibly has a flame problem. There could be an issue with its gas supply, gas valve or ignitor control. Call us at 325-200-4667 for assistance.
  8. An individual light flickers slowly while the other remains solid. This typically indicates your furnace’s limit switch is not working. The switch stops your furnace from overheating. Get in touch with the experts at Abilene Air-Tech Inc for support.

Furnace Blower Runs But No Warmth

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

  • Both lights are showing alternate fast blinks. This means your furnace ignitor could be broken. This piece lights energy in your furnace to make warm air and should be fixed by a specialist from Abilene Air-Tech Inc.

Depend on Us for Expert Furnace Repair

When you need to get your heating system repaired without delay, turn to the professionals at Abilene Air-Tech Inc. Our technicians will fix the error promptly and have your house feeling comfortable again soon. Call us at (325) 692-5850 or contact us online to schedule an appointment today.


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