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

December 06, 2019

While your Lennox® heating system cannot speak to you, it does have a process to tell you about a furnace error.

Its control board has double LED lights that can display a fault code. Based on the malfunction, your furnace could show steady or flashing lights.

While there are various simple furnace fixes you can complete yourself, the majority of fixes are best left to experts. When your heating system won’t start or give heat, reach out to Watts Electric & A/C Inc at 601-736-7362 for experienced furnace repair in Columbia.

Our specialists will speedily determine and repair the breakdown, even if you don’t own a Lennox furnace. We can fix any brands or models—and get the warmth restored to your residence without delay.


What Does the Flashing Light on My Heater Mean?

Your heating system depends on lights to flash code when it requires repairs. It also uses these lights to tell you it’s heating like it should.

Normal function includes:

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

If you see one light going on and off slowly and the other blinking rapidly, your heater might have a low flame signal. This can happen even when your furnace is operating properly. It indicates the flame sensing rod might need to be cleaned or in the wrong location on the burner. Contact us at 601-736-7362 for support.

Here are some of the most typical problems for Lennox HVAC systems.

Furnace Will Not Turn On

Here are many of the light sequences you might see when your heating system won’t turn on or stay on. The bulk of these problems must be taken care of by a technician, like one from Watts Electric & A/C Inc.

  1. The duo of LED lights are extinguished. This means your furnace might not have electricity. Look at the breaker box to ensure the furnace fuse has not tripped. You should reset the fuse if it has moved into the “off” area. If it rapidly turns off after you reset it, leave the breaker alone and get in touch with us us at 601-736-7362.
  2. One light is unchanging and the other is blinking slowly. This shows the flame rollout switch is likely malfunctioning. The component is an important safety tool that helps in stopping fires and carbon monoxide. You shouldn’t attempt to take care of this issue yourself.
  3. A single light is flickering quickly and the other is blinking slowly. This often means power polarity has been inverted. Your heating system could have a wiring fault that requires professional aid from Watts Electric & A/C Inc.
  4. All lights are flashing slowly. This signifies your furnace’s blower motor possibly isn’t running. This component circulates heated air from the HVAC 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 means your heating system might have low voltage or a short circuit. Call our professionals at 601-736-7362 for support.
  6. One light is flickering on, on and off while the other flashes on, off, on. This signifies there could be trouble with your HVAC system’s motherboard or wiring. Watts Electric & A/C Inc can locate the problem and fix it.
  7. The duo of lights show alternate slow blinks. This signifies your HVAC equipment likely has a flame failure. There might be trouble with its gas supply, gas valve or ignitor control. Contact us at 601-736-7362 for help.
  8. A single light flashes slowly while the other is continuous. This often means your furnace’s limit switch is experiencing an error. The switch prevents your heating system from getting too hot. Get in touch with the specialists at Watts Electric & A/C Inc for support.

Furnace Blower Works But No Heat

Here’s what might be wrong when you notice your heater’s blower fan working, but you aren’t getting any warm air.

  • The pair of lights display alternating quick blinks. This indicates your furnace ignitor may not be in working order. This component kindles energy in your furnace to produce warm air and should be fixed by an expert from Watts Electric & A/C Inc.

Turn to Us for Expert Furnace Repair

When you need to get your heating system repaired without delay, turn to the specialists at Watts Electric & A/C Inc. Our pros will take care of the fault right away and have your space feeling comfortable again soon. Get in touch with us at 601-736-7362 or contact us online to get an appointment now.