Furnace troubleshooting

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

While your Lennox® furnace cannot talk to you, it does have a method to tell you about a furnace error.

Its control board has a set of LED lights that can share a fault code. Subject to the problem, your heater may use solid or flashing lights.

Though there are some simple furnace fixes you can finish on your own, most services are best taken care of by HVAC technicians. When your heating system won’t turn on or give warmth, call Morgner Inc. Air Conditioning & Heating at 314-262-4541 for experienced furnace repair in St. Louis.

Our experts will speedily determine and take care of the failure, even if you don’t own a Lennox furnace. We can fix whichever kinds or makes—and get the warmth restored to your house fast.


What Does the Blinking Light on My Heating System Mean?

Your furnace depends on lights to flash code when it needs to be repaired. It also uses this setup to relay it’s running correctly.

Correct function involves:

  • Concurrent slow flash—heater working like it should.
  • Simultaneous fast flash—furnace is starting to call for heat.

If you see a solitary light going on and off slowly and the other going on and off fast, your furnace might be having a low flame signal. This can occur even when your furnace is working properly. It signifies the flame sensing rod could need to be cleaned or in the wrong spot on the burner. Reach out to us at 314-262-4541 for help.

Here are several other of the most common problems for Lennox furnaces.

Furnace Refuses to Start

Here are many of the light patterns you may see when your heat refuses to or stay on. The majority of these issues need to be repaired by a professional, for instance from Morgner Inc. Air Conditioning & Heating.

  1. The pair of LED lights are off. This indicates your HVAC system might not be receiving power. Examine the breaker box to ensure the heating system fuse has not tripped. Attempt to reset the fuse if it is in the “off” spot. If it promptly trips after you reset it, don’t try to reset it again and call us at 314-262-4541.
  2. A single light is stable and the other is blinking slowly. This signifies the flame rollout switch is likely not working right. The switch is an important safety tool that helps in avoiding fires and carbon monoxide. You shouldn’t attempt to handle this malfunction on your own.
  3. An individual light is blinking quickly and the other is blinking slowly. This usually indicates power polarity has been reversed. Your heating system could have a wiring problem that needs professional help from Morgner Inc. Air Conditioning & Heating.
  4. All lights are flashing slowly. This means your heater’s blower motor possibly isn’t working. This part moves warm air from the heater into your space. We can help in figuring out what’s causing an issue with this part.
  5. One light is flickering slowly and the other is blinking rapidly. This signifies your HVAC system might have insufficient voltage or a short circuit. Get in touch with our technicians at 314-262-4541 for support.
  6. One light is flashing on, on and off while the other flickers on, off, on. This indicates there may be trouble with your heater’s control board or wiring. Morgner Inc. Air Conditioning & Heating can determine the issue and take care of it.
  7. Both lights are using alternate slow flashes. This signifies your HVAC system may have a flame problem. There could be an issue with its gas supply, gas valve or ignitor control. Contact us at 314-262-4541 for help.
  8. An individual light flashes slowly while the other is solid. This typically indicates your heating system’s limit switch is not working. The switch keeps your heating system from becoming too warm. Contact the experts at Morgner Inc. Air Conditioning & Heating for support.

Heating System Blower Works But No Heat

Here’s what might be wrong when you hear your furnace’s blower fan on, but you aren’t getting any heated air.

  • The duo of lights are giving every other rapid flickers. This means your furnace ignitor could be broken. This component kindles gas in your heater to produce warmth and should be serviced by an expert from Morgner Inc. Air Conditioning & Heating.

Trust Us for Professional Furnace Repair

When you need to have your heating system in working order without delay, turn to the experts at Morgner Inc. Air Conditioning & Heating. Our pros will handle the error promptly and have your rooms feeling relaxing again soon. Get in touch with us at 314-262-4541 or contact us online to schedule an appointment today.

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