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

December 06, 2019

While your Lennox® heating system isn’t able to talk to you, it has a method to communicate a furnace error.

Its motherboard has two LED lights that can display a fault code. Subject to the fault, your heater could show solid or flashing lights.

Although there are some elementary HVAC fixes you can take care of yourself, most services are best taken care of by HVAC technicians. When your furnace refuses to start or provide heat, get in touch with American HVAC Inc at 408-215-1018 for expert furnace repair in San Jose.

Our technicians will rapidly pinpoint and handle the problem, even if you don’t use a Lennox heating system. We can repair all kinds or configuration—and get the comfort restored to your house quickly.


What Does the Flashing Light on My Furnace Mean?

Your heater uses lights to flash code when it needs to be repaired. It also uses this setup to tell you it’s running correctly.

Regular operation involves:

  • Both lights flash slowly—heating system operating properly.
  • Simultaneous fast flash—heater is initiating the call for heat.

If you realize that a single light blinking slowly and the other blinking fast, your furnace could be experiencing a low flame signal. This can occur even when your furnace is operating like it should. It indicates the flame sensing rod might have build-up or in the bad area on the burner. Contact us at 408-215-1018 for help.

Here are a few other of the most routine faults for Lennox HVAC systems.

Heater Won’t Start

Here are many of the light patterns you might see when your furnace will not or stay on. The majority of these issues need to be handled by a professional, like one from American HVAC Inc.

  1. The duo of LED lights are extinguished. This signifies your heater might not have power. Examine the breaker box to make sure the heater fuse hasn’t flipped. Try resetting the fuse if it is in the “off” spot. If it promptly trips after you reset it, leave the breaker alone and get in touch with us us at 408-215-1018.
  2. One light is stable and the other is blinking slowly. This means the flame rollout switch is likely not working right. The switch is an important safety tool that aids in avoiding fires and carbon monoxide. You shouldn’t attempt to repair this malfunction without professional help.
  3. One light is flickering rapidly and the other is flickering slowly. This usually indicates power polarity has been transposed. Your heating system might have a wiring issue that calls for specialized assistance from American HVAC Inc.
  4. Both lights are blinking slowly. This indicates your furnace’s blower motor possibly isn’t operating. This component distributes heated air from the heater into your house. We can help in pinpointing what’s wrong with this component.
  5. An individual light is blinking slowly and the other is blinking rapidly. This means your furnace could have not enough voltage or a short circuit. Reach out to our professionals at 408-215-1018 for help.
  6. One light is blinking on, on and off while the other flickers on, off, on. This signifies there may be an error with your HVAC system’s control panel or wiring. American HVAC Inc can determine the error and handle it.
  7. The duo of lights display alternate slow flashes. This means your heating system likely has a flame error. There could be trouble with its gas supply, gas valve or ignitor control. Get in touch with us at 408-215-1018 for support.
  8. An individual light blinks slowly while the other stays steady. This typically signifies your heater’s limit switch is malfunctioning. The switch stops your heating system from getting too hot. Contact the pros at American HVAC Inc for help.

Heater Blower Works 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 showing alternate quick flickers. This signifies your furnace ignitor might not be in working order. This part lights gas in your heater to produce heat and should be repaired by a professional from American HVAC Inc.

Trust Us for Expert Furnace Repair

When you have to have your heater in working order fast, depend on the experts at American HVAC Inc. Our techs will take care of the problem promptly and have your house feeling cozy again in a short time. Contact us at 408-215-1018 or contact us online to request an appointment right away.

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