Furnace troubleshooting

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

While your Lennox® heating system isn’t able to chat with you, it does have a method to communicate a furnace error.

Its control panel has a set of LED lights that can share a fault code. Based on the failure, your furnace could show continuous or flashing lights.

Though there are some basic furnace fixes you can finish without an expert, most repairs are best handled by experts. When your furnace won’t kick on or deliver warm air, reach out to Air Alliance Team at 636-498-0051 for expert furnace repair in Ballwin.

Our technicians will rapidly pinpoint and fix the malfunction, even if you don’t use a Lennox furnace. We can repair whichever kinds or configuration—and get the heat returned to your home fast.


What Does the Blinking Light on My Heating System Mean?

Your heater depends on lights to flash code when it is malfunctioning. It also works these lights to let you know it’s running correctly.

Correct operation includes:

  • Both lights flash slowly—furnace working like it should.
  • Both lights flash fast—furnace is beginning to call for heat.

If you realize that a lone light flashing slowly and the other blinking fast, your heating system might be having a low flame signal. This can happen even when your heater is running properly. It means the flame sensing rod might have build-up or in the wrong spot on the burner. Reach out to us at 636-498-0051 for assistance.

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

Heating System Will Not Turn On

Here are a few of the light patterns you may see when your heater won’t turn on or keep heating. The bulk of these issues need to be fixed by a professional, such as one from Air Alliance Team.

  1. Both LED lights are extinguished. This signifies your heater might not have power. Look at the breaker box to make sure the heating system fuse isn’t tripped. Try resetting the fuse if it’s in the “off” position. If it rapidly turns off after you reset it, leave the breaker alone and get in touch with us us at 636-498-0051.
  2. An individual light is stable and the other is flickering slowly. This implies the flame rollout switch is probably malfunctioning. The part is an important safety mechanism that helps in preventing fires and carbon monoxide. You shouldn’t seek to handle this problem yourself.
  3. One light is flickering fast and the other is blinking slowly. This typically means power polarity has been reversed. Your heater might have a wiring problem that needs expert assistance from Air Alliance Team.
  4. Both lights are flickering slowly. This indicates your heater’s blower motor probably isn’t operating. This component distributes hot air from the heater into your rooms. We can assist in determining what’s causing an issue with this part.
  5. A single light is blinking slowly and the other is blinking quickly. This means your heating system may have not enough voltage or a short circuit. Contact our specialists at 636-498-0051 for assistance.
  6. One light is blinking on, on and off while the other flickers on, off, on. This signifies there might be an error with your heater’s motherboard or wiring. Air Alliance Team can pinpoint the issue and fix it.
  7. Both lights display every other slow blinks. This signifies your heater possibly has a flame failure. There might be an issue with its gas supply, gas valve or ignitor control. Contact us at 636-498-0051 for support.
  8. An individual light flashes slowly while the other remains continuous. This often signifies your heating system’s limit switch is open. The switch keeps your heating system from getting too hot. Contact the pros at Air Alliance Team for support.

Heater Blower Runs But No Warm Air

Here’s what may be wrong when you observe your heating equipment’s blower fan running, but you aren’t gaining any warm air.

  • The duo of lights are giving alternating fast blinks. This indicates your furnace ignitor could not be in working order. This component ignites fuel in your heater to produce warmth and should be serviced by an expert from Air Alliance Team.

Turn to Us for Skilled Furnace Repair

When you have to get your furnace in working order quickly, turn to the professionals at Air Alliance Team. Our techs will repair the fault quickly and have your house feeling cozy again soon. Call us at 636-498-0051 or contact us online to schedule an appointment right away.

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