Furnace troubleshooting

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

While your Lennox® heating system can’t speak to you, it does have a procedure to communicate a furnace error.

Its motherboard has two LED lights that can display a fault code. Based on the problem, your heating system could show steady or flashing lights.

Although there are certain basic furnace fixes you can complete on your own, most fixes are best handled by experts. When your heating system refuses to start or provide heated air, get in touch with Airmax Long Island Inc at 631-737-5566 for professional furnace repair in Suffolk/Nassau County.

Our experts will rapidly determine and handle the breakdown, even if you don’t have a Lennox heater. We can service any kinds or makes—and get the comfort restored to your home fast.


What Does the Flashing Light on My Heating System Mean?

Your heater relies on lights to flash code when it needs to be repaired. It also uses this setup to let you know it’s operating like it should.

Normal operation includes:

  • Simultaneous slow flash—furnace heating correctly.
  • Both lights flash fast—furnace is starting to call for heat.

If you notice one light going on and off slowly and the other blinking fast, your heating system may be having a low flame signal. This can happen even when your heating system is working like it should. It signifies the flame sensing rod might be dirty or in the wrong spot on the burner. Reach out to us at 631-737-5566 for support.

Here are a few other of the most common faults for Lennox heating systems.

Heating System Will Not Kick On

Here are many of the light patterns you could observe when your heater refuses to or stay on. Most of these errors must be taken care of by a specialist, such as one from Airmax Long Island Inc.

  1. The pair of LED lights are extinguished. This indicates your heater might not have power. Find the breaker box to confirm the furnace fuse has not triggered. Attempt to reset the fuse if it is in the “off” area. If it promptly trips after a subsequent reset, leave the breaker alone and call us at 631-737-5566.
  2. One light is stable and the other is flashing slowly. This implies the flame rollout switch is may be malfunctioning. The component is a critical safety mechanism that aids in avoiding fires and carbon monoxide. You shouldn’t try to fix this problem without professional help.
  3. A single light is flickering rapidly and the other is flickering slowly. This likely signifies power polarity has been transposed. Your furnace could have a wiring fault that calls for specialized help from Airmax Long Island Inc.
  4. The pair of lights are flashing slowly. This indicates your furnace’s blower motor possibly isn’t working. This part distributes warm air from the heater into your home. We can aid in determining what’s causing a problem 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 experts at 631-737-5566 for assistance.
  6. One light is flickering on, on and off while the other blinks on, off, on. This indicates there may be a fault with your furnace’s motherboard or wiring. Airmax Long Island Inc can locate the issue and handle it.
  7. The duo of lights show alternating slow flickers. This signifies your heating system possibly has a flame error. There may be an issue with its gas supply, gas valve or ignitor control. Get in touch with us at 631-737-5566 for help.
  8. An individual light flashes slowly while the other stays continuous. This often means your HVAC system’s limit switch is malfunctioning. The switch stops your furnace from overheating. Reach out to the professionals at Airmax Long Island Inc for help.

Furnace Blower Operates But No Heat

Here’s what may be broken when you observe your heating system’s blower fan working, but you aren’t getting any warmth.

  • The duo of lights are giving alternate quick blinks. This signifies your furnace ignitor may not be in working order. This piece ignites gas in your heating system to produce heat and should be fixed by a technician from Airmax Long Island Inc.

Trust Us for Skilled Furnace Repair

When you have to have your heating system repaired quickly, trust the experts at Airmax Long Island Inc. Our pros will repair the issue without delay and have your house feeling cozy again soon. Call us at 631-737-5566 or contact us online to schedule an appointment now.

Back To Blog