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

December 06, 2019

While your Lennox® HVAC equipment cannot chat with you, it has a method to get your attention when there’s a furnace error.

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

While there are various elementary heating adjustments you can take care of without an expert, the majority of tasks are best handled by experts. When your heater won’t kick on or give warmth, get in touch with Strine's Heating & Air Conditioning at 717-383-4479 for expert furnace repair in York.

Our experts will speedily spot and handle the problem, even if you don’t use a Lennox heater. We can repair any types or models—and get the comfort returned to your home fast.


What Does the Flashing Light on My Heater Mean?

Your furnace uses lights to flash code when it needs to be repaired. It also works this system to relay it’s heating like it should.

Correct heating involves:

  • Concurrent slow flash—heating system heating properly.
  • Simultaneous fast flash—heater is starting to call for heat.

If you notice a single light flashing slowly and the other going on and off rapidly, your heater might be having a low flame signal. This can occur even when your heating system is heating correctly. It signifies the flame sensing rod may be dirty or in the wrong area on the burner. Contact us at 717-383-4479 for help.

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

Heating System Won’t Start

Here are a few of the light sequences you may see when your heat refuses to or keep running. The majority of these issues need to be handled by a professional, like one from Strine's Heating & Air Conditioning.

  1. Both LED lights are extinguished. This signifies your heater might not have power. Find the breaker box to ensure the heating system fuse hasn’t triggered. Try resetting the fuse if it’s in the “off” position. If it promptly trips following a reset, leave the breaker alone and contact us at 717-383-4479.
  2. A single light is solid and the other is flickering slowly. This signifies the flame rollout switch is likely not working right. The switch is an essential safety guard that assists in avoiding fires and carbon monoxide. You shouldn’t attempt to take care of this fault without professional help.
  3. An individual light is flickering rapidly and the other is blinking slowly. This likely signifies power polarity has been reversed. Your heating system may have a wiring fault that needs professional support from Strine's Heating & Air Conditioning.
  4. The pair of lights are flashing slowly. This indicates your furnace’s blower motor probably isn’t operating. This component distributes warm air from the heating system into your residence. We can assist in determining what’s causing an issue with this component.
  5. One light is flickering slowly and the other is blinking quickly. This indicates your furnace might have low voltage or a short circuit. Get in touch with our professionals at 717-383-4479 for assistance.
  6. One light is flashing on, on and off while the other flickers on, off, on. This indicates there could be trouble with your furnace’s motherboard or wiring. Strine's Heating & Air Conditioning can find the error and repair it.
  7. The duo of lights are using alternate slow blinks. This signifies your heating system possibly has a flame error. There could be a problem with its gas supply, gas valve or ignitor control. Reach out to us at 717-383-4479 for help.
  8. A single light flickers slowly while the other is steady. This typically means your heater’s limit switch is malfunctioning. The switch stops your heating system from overheating. Reach out to the specialists at Strine's Heating & Air Conditioning for assistance.

Furnace Blower Operates But No Warmth

Here’s what could be at fault when you notice your furnace’s blower fan on, but you aren’t getting any heat.

  • Both lights are showing every other rapid blinks. This means your furnace ignitor may not be working. This component ignites fuel in your HVAC equipment to produce warmth and should be repaired by a professional from Strine's Heating & Air Conditioning.

Depend on Us for Professional Furnace Repair

When you have to get your heater in working order quickly, depend on the specialists at Strine's Heating & Air Conditioning. Our pros will fix the error without delay and have your residence feeling comfortable again in no time. Get in touch with us at 717-383-4479 or contact us online to request an appointment now.