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

December 06, 2019

While your Lennox® furnace isn’t able to speak to you, it possesses a process to tell you about a furnace error.

Its control panel has two LED lights that can share a fault code. Subject to the problem, your furnace could show solid or flashing lights.

While there are certain basic heating repairs you can do without an expert, the majority of tasks are best left to the professionals. When your heater will not turn on or put out heat, get in touch with Cytech Heating & Cooling L.C. at 956-630-3522 for experienced furnace repair in the Rio Grande Valley.

Our experts will swiftly diagnose and repair the problem, even if you don’t have a Lennox furnace. We can repair whichever brands or makes—and get the heat returned to your residence quickly.


What Does the Flashing Light on My Heater Mean?

Your furnace depends on lights to flash code when it is malfunctioning. It also uses this system to tell you it’s heating like it should.

Correct function involves:

  • Both lights flash slowly—heating system heating like it should.
  • Both lights flash fast—heater is beginning to call for heat.

If you see a lone light going on and off slowly and the other flashing rapidly, your furnace may be experiencing a low flame signal. This can occur even when your furnace is operating like it should. It indicates the flame sensing rod might need to be cleaned or in the incorrect area on the burner. Call us at 956-630-3522 for help.

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

Heating System Will Not Turn On

Here are a few of the light arrangements you might notice when your heating system won’t turn on or keep operating. Most of these problems have to be repaired by a specialist, such as one from Cytech Heating & Cooling L.C..

  1. The duo of LED lights aren’t lit. This indicates your heating system might not be receiving power. Go to the breaker box to make sure the heater fuse isn’t triggered. You should reset the fuse if it’s in the “off” position. If it instantly turns off following a reset, don’t touch the breaker and call us at 956-630-3522.
  2. An individual light is unchanging and the other is flickering slowly. This means the flame rollout switch is may be malfunctioning. The part is an essential safety device that helps in preventing fires and carbon monoxide. You shouldn’t attempt to fix this malfunction yourself.
  3. An individual light is blinking quickly and the other is flickering slowly. This likely indicates power polarity has been reversed. Your furnace may have a wiring error that requires professional support from Cytech Heating & Cooling L.C..
  4. The duo of lights are flashing slowly. This means your furnace’s blower motor likely isn’t working. This component moves warm air from the heater into your house. We can assist in determining what’s causing an issue with this piece.
  5. A single light is flashing slowly and the other is flashing rapidly. This indicates your heater could have insufficient voltage or a short circuit. Call our experts at 956-630-3522 for support.
  6. One light is flickering on, on and off while the other blinks on, off, on. This indicates there could be a malfunction with your heater’s control panel or wiring. Cytech Heating & Cooling L.C. can determine the fault and fix it.
  7. Both lights are using every other slow blinks. This signifies your furnace likely has a flame failure. There may be a problem with its gas supply, gas valve or ignitor control. Contact us at 956-630-3522 for assistance.
  8. A single light blinks slowly while the other remains solid. This usually means your heating system’s limit switch is malfunctioning. The switch keeps your HVAC equipment from overheating. Contact the professionals at Cytech Heating & Cooling L.C. for help.

Heater Blower Runs But No Heat

Here’s what may be broken when you hear your heating equipment’s blower fan on, but you aren’t receiving any warmth.

  • Both lights are giving alternate rapid blinks. This means your furnace ignitor may be broken. This piece lights gas in your heating system to produce warmth and should be fixed by a professional from Cytech Heating & Cooling L.C..

Trust Us for Professional Furnace Repair

When you have to have your heating system fixed without delay, trust the professionals at Cytech Heating & Cooling L.C.. Our techs will repair the problem quickly and have your space feeling relaxing again in no time. Call us at 956-630-3522 or contact us online to get an appointment right away.