Furnace troubleshooting

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

While your Lennox® furnace can’t speak to you, it has a process to get your attention when there’s a furnace error.

Its control board has a set of LED lights that can show a fault code. Depending on the failure, your heater could use continuous or flashing lights.

Although there are various simple HVAC fixes you can finish on your own, most services are best taken care of by experts. When your heater won’t turn on or deliver warm air, get in touch with James Heating & A/C, Inc at 336-853-6070 for professional furnace repair in Lexington.

Our experts will swiftly spot and handle the fault, even if you don’t own a Lennox heating system. We can fix all brands or configuration—and get the comfort reintroduced to your house without delay.


What Does the Flashing Light on My Heating System Mean?

Your furnace relies on lights to flash code when it is malfunctioning. It also engages this setup to tell you it’s operating properly.

Normal operation includes:

  • Simultaneous slow flash—heating system running properly.
  • Simultaneous fast flash—heating system is initiating the call for heat.

If you notice one light blinking slowly and the other flashing fast, your heater could be experiencing a low flame signal. This can happen even when your heater is heating like it should. It indicates the flame sensing rod might be dirty or in the incorrect area on the burner. Call us at 336-853-6070 for help.

Here are some of the most routine faults for Lennox heating systems.

Heater Refuses to Start

Here are a few of the light patterns you could see when your heater refuses to or keep running. The bulk of these issues need to be repaired by an expert, for instance from James Heating & A/C, Inc.

  1. Both LED lights are extinguished. This indicates your heating system might not have power. Examine the breaker box to confirm the furnace fuse has not flipped. You should reset the fuse if it has moved into the “off” position. If it promptly flips after a subsequent reset, don’t try to reset it again and get in touch with us us at 336-853-6070.
  2. An individual light is unchanging and the other is blinking slowly. This means the flame rollout switch is probably not working right. The component is an essential safety guard that assists in avoiding fires and carbon monoxide. You shouldn’t try to repair this issue yourself.
  3. A single light is flickering rapidly and the other is flickering slowly. This often indicates power polarity has been reversed. Your furnace might have a wiring error that calls for specialized aid from James Heating & A/C, Inc.
  4. The pair of lights are blinking slowly. This means your heating system’s blower motor likely isn’t running. This component moves warm air from the heating system into your house. We can aid in pinpointing what’s causing an issue with this piece.
  5. A single light is blinking slowly and the other is blinking fast. This signifies your heating system could have not enough voltage or a short circuit. Reach out to our specialists at 336-853-6070 for assistance.
  6. One light is blinking on, on and off while the other blinks on, off, on. This indicates there could be a malfunction with your heater’s control board or wiring. James Heating & A/C, Inc can determine the problem and repair it.
  7. Both lights show alternating slow flashes. This means your HVAC system possibly has a flame issue. There might be a problem with its gas supply, gas valve or ignitor control. Contact us at 336-853-6070 for assistance.
  8. An individual light flashes slowly while the other stays steady. This usually indicates your furnace’s limit switch is open. The switch keeps your heater from getting too hot. Reach out to the pros at James Heating & A/C, Inc for help.

Heating System Blower Works But No Warmth

Here’s what may be broken when you notice your furnace’s blower fan running, but you aren’t receiving any warm air.

  • Both lights are showing alternate quick flashes. This indicates your furnace ignitor may be broken. This component ignites energy in your heating system to create heat and should be repaired by an expert from James Heating & A/C, Inc.

Depend on Us for Expert Furnace Repair

When you have to get your heater repaired quickly, turn to the technicians at James Heating & A/C, Inc. Our pros will repair the fault right away and have your residence feeling relaxing again soon. Reach out to us at 336-853-6070 or contact us online to schedule an appointment now.

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