Furnace troubleshooting

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

While your Lennox® HVAC equipment isn’t able to speak to you, it possesses a method to tell you about a furnace error.

Its control board has twin LED lights that can display a fault code. Based on the issue, your furnace may show continuous or flashing lights.

Though there are certain elementary HVAC adjustments you can finish on your own, many services are best handled by experts. When your heater refuses to kick on or give warm air, call Air Alliance Team at 636-229-1544 for expert furnace repair in Saint Charles.

Our experts will rapidly pinpoint and take care of the issue, even if you don’t own a Lennox furnace. We can service any brands or configuration—and get the comfort restored to your residence quickly.


What Does the Flashing Light on My Furnace Mean?

Your heating system relies on lights to flash code when it is malfunctioning. It also works this system to relay it’s heating like it should.

Normal operation consists of:

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

If you notice a single light flashing slowly and the other blinking fast, your heating system may be having a low flame signal. This can occur even when your heater is working like it should. It means the flame sensing rod might be dirty or in the wrong spot on the burner. Reach out to us at 636-229-1544 for support.

Here are a few other of the most typical errors for Lennox HVAC systems.

Furnace Refuses to Turn On

Here are some of the light sequences you may observe when your heater won’t turn on or keep operating. The majority of these issues have to be repaired by an expert, such as one from Air Alliance Team.

  1. Both LED lights are extinguished. This indicates your heater might not have power. Examine the breaker box to make sure the furnace fuse is not triggered. Attempt to reset the fuse if it is in the “off” spot. If it promptly flips after a subsequent reset, don’t touch the breaker and call us at 636-229-1544.
  2. One light is solid and the other is blinking slowly. This implies the flame rollout switch is probably not working right. The part is an important safety mechanism that aids in stopping fires and carbon monoxide. You shouldn’t seek to take care of this problem without professional help.
  3. An individual light is flashing quickly and the other is flashing slowly. This typically indicates power polarity has been reversed. Your heating system may have a wiring fault that requires professional aid from Air Alliance Team.
  4. The duo of lights are flickering slowly. This means your heater’s blower motor probably isn’t operating. This part sends hot air from the furnace into your home. We can assist in determining what’s wrong with this component.
  5. A single light is flickering slowly and the other is flickering rapidly. This means your HVAC system might have insufficient voltage or a short circuit. Call our specialists at 636-229-1544 for assistance.
  6. One light is flickering on, on and off while the other flashes on, off, on. This signifies there might be trouble with your heating system’s motherboard or wiring. Air Alliance Team can determine the problem and take care of it.
  7. Both lights display every other slow blinks. This means your furnace likely has a flame failure. There might be trouble with its gas supply, gas valve or ignitor control. Get in touch with us at 636-229-1544 for support.
  8. An individual light flickers slowly while the other is steady. This usually signifies your HVAC system’s limit switch is experiencing an error. The switch stops your heater from getting too hot. Contact the professionals at Air Alliance Team for assistance.

Heating System Blower Works But No Heat

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

  • The duo of lights are giving alternating rapid flashes. This indicates your furnace ignitor could not be working. This part kindles gas in your heating system to produce warm air and should be fixed by a technician from Air Alliance Team.

Depend on Us for Professional Furnace Repair

When you need to get your heater fixed fast, depend on the experts at Air Alliance Team. Our techs will handle the issue without delay and have your residence feeling cozy again soon. Reach out to us at 636-229-1544 or contact us online to get an appointment right away.

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