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

December 06, 2019

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

Its control board has two LED lights that can share a fault code. Subject to the failure, your heating system may display continuous or flashing lights.

Though there are various basic heating adjustments you can finish yourself, many services are best left to the professionals. When your heating system refuses to kick on or provide warm air, reach out to Pepper AC & Htg Inc at 940-202-1184 for expert furnace repair in Justin.

Our technicians will quickly identify and handle the breakdown, even if you don’t own a Lennox heating system. We can fix any types or configuration—and get the comfort reintroduced to your house without delay.


What Does the Blinking Light on My Heater Mean?

Your furnace relies on lights to flash code when it isn’t working right. It also works this setup to relay it’s working properly.

Correct function includes:

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

If you realize that one light going on and off slowly and the other going on and off rapidly, your heater may have a low flame signal. This can take place even when your furnace is heating properly. It means the flame sensing rod might have build-up or in the incorrect spot on the burner. Contact us at 940-202-1184 for help.

Here are a few other of the most typical errors for Lennox furnaces.

Heater Refuses to Turn On

Here are a few of the light sequences you might observe when your furnace won’t turn on or keep running. The majority of these issues have to be fixed by an expert, such as one from Pepper AC & Htg Inc.

  1. All LED lights are extinguished. This signifies your heater might not have electricity. Look at the breaker box to confirm the furnace fuse isn’t tripped. Try resetting the fuse if it’s in the “off” position. If it instantly flips after a subsequent reset, don’t touch the breaker and get in touch with us us at 940-202-1184.
  2. An individual light is continuous and the other is blinking slowly. This means the flame rollout switch is probably not working right. The switch is an important safety tool that aids in preventing fires and carbon monoxide. You shouldn’t try to handle this issue yourself.
  3. An individual light is flickering quickly and the other is blinking slowly. This likely means power polarity has been reversed. Your heating system could have a wiring problem that calls for professional assistance from Pepper AC & Htg Inc.
  4. The duo of lights are blinking slowly. This indicates your heating system’s blower motor probably isn’t operating. This part circulates warm air from the heating system into your rooms. We can aid in determining what’s causing an issue with this part.
  5. One light is flickering slowly and the other is flashing fast. This means your heating system may have insufficient voltage or a short circuit. Contact our professionals at 940-202-1184 for assistance.
  6. One light is flashing on, on and off while the other blinks on, off, on. This signifies there may be an issue with your furnace’s control panel or wiring. Pepper AC & Htg Inc can pinpoint the issue and handle it.
  7. The pair of lights are using alternating slow blinks. This signifies your heating system likely has a flame failure. There could be trouble with its gas supply, gas valve or ignitor control. Get in touch with us at 940-202-1184 for help.
  8. A single light flashes slowly while the other remains solid. This typically signifies your furnace’s limit switch is malfunctioning. The switch keeps your heating system from getting too hot. Get in touch with the pros at Pepper AC & Htg Inc for help.

Heating System Blower Runs But No Warm Air

Here’s what may be wrong when you hear your heating system’s blower fan on, but you aren’t gaining any warmth.

  • The pair of lights display alternate rapid blinks. This signifies your furnace ignitor might not be in working order. This piece ignites fuel in your furnace to make warm air and should be fixed by an expert from Pepper AC & Htg Inc.

Turn to Us for Skilled Furnace Repair

When you need to get your HVAC equipment fixed quickly, trust the experts at Pepper AC & Htg Inc. Our techs will handle the error right away and have your residence feeling cozy again in a short time. Contact us at 940-202-1184 or contact us online to request an appointment right away.