Top Lennox® Furnace Error Codes (and What They Mean)

December 06, 2019

While your Lennox® heater cannot chat with you, it has a method to tell you about a furnace error.

Its control panel has twin LED lights that can show a fault code. Subject to the issue, your heating system might use steady or flashing lights.

While there are certain basic heating adjustments you can take care of on your own, most repairs are best left to HVAC technicians. When your heating system will not start or put out warmth, contact ACS Heating and Air Conditioning at 770-450-1539 for experienced furnace repair in Tucker.

Our technicians will rapidly spot and take care of the failure, even if you don’t own a Lennox heating system. We can fix any kinds or configuration—and get the comfort reintroduced to your home fast.


What Does the Flashing Light on My Furnace Mean?

Your heater depends on lights to flash code when it needs to be repaired. It also works these lights to let you know it’s operating correctly.

Regular operation involves:

  • Both lights flash slowly—heater running properly.
  • Both lights flash fast—heating system is beginning to call for heat.

If you notice one light flashing slowly and the other blinking fast, your heating system might be having a low flame signal. This can occur even when your heating system is operating correctly. It indicates the flame sensing rod may need to be cleaned or in the bad area on the burner. Reach out to us at 770-450-1539 for assistance.

Here are a few other of the most routine faults for Lennox HVAC systems.

Heating System Will Not Turn On

Here are some of the light arrangements you may observe when your heat will not or keep heating. The bulk of these issues must be fixed by a professional, like one from ACS Heating and Air Conditioning.

  1. Both LED lights are off. This means your HVAC system might not be receiving power. Check the breaker box to make sure the furnace fuse isn’t tripped. Try resetting the fuse if it is in the “off” spot. If it promptly trips after a subsequent reset, leave the breaker alone and contact us at 770-450-1539.
  2. An individual light is unchanging and the other is flashing slowly. This implies the flame rollout switch is likely malfunctioning. The switch is a critical safety tool that assists in avoiding fires and carbon monoxide. You shouldn’t seek to handle this issue without professional help.
  3. An individual light is flashing rapidly and the other is flickering slowly. This usually means power polarity has been inverted. Your heating system could have a wiring issue that requires expert assistance from ACS Heating and Air Conditioning.
  4. Both lights are blinking slowly. This means your heating system’s blower motor possibly isn’t operating. This part moves warm air from the heating system into your home. We can assist in pinpointing what’s causing a problem with this part.
  5. A single light is blinking slowly and the other is flashing quickly. This means your heater may have low voltage or a short circuit. Reach out to our technicians at 770-450-1539 for help.
  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 control board or wiring. ACS Heating and Air Conditioning can pinpoint the fault and take care of it.
  7. The duo of lights show every other slow blinks. This signifies your heating system possibly has a flame issue. There may be a problem with its gas supply, gas valve or ignitor control. Contact us at 770-450-1539 for assistance.
  8. An individual light flashes slowly while the other stays continuous. This typically signifies your HVAC equipment’s limit switch is open. The switch keeps your heating system from becoming too warm. Reach out to the professionals at ACS Heating and Air Conditioning for support.

Furnace Blower Works But No Warmth

Here’s what might be at fault when you hear your furnace’s blower fan on, but you aren’t gaining any warmth.

  • Both lights display alternate rapid flickers. This signifies your furnace ignitor might not be in working order. This piece kindles energy in your furnace to create warm air and should be fixed by a professional from ACS Heating and Air Conditioning.

Depend on Us for Expert Furnace Repair

When you have to have your heating system in working order fast, trust the professionals at ACS Heating and Air Conditioning. Our technicians will handle the issue promptly and have your space feeling comfortable again in a short time. Contact us at 770-450-1539 or contact us online to request an appointment right away.