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

December 06, 2019

While your Lennox® heater isn’t able to chat with you, it possesses a procedure to tell you about a furnace error.

Its motherboard has a set of LED lights that can display a fault code. Depending on the issue, your furnace could show steady or flashing lights.

Though there are various simple furnace repairs you can finish without an expert, most fixes are best left to HVAC technicians. When your heater refuses to kick on or provide warm air, get in touch with Knoechel Heating Company at 724-425-5852 for expert furnace repair in Zelienople.

Our experts will rapidly spot and handle the failure, even if you don’t own a Lennox furnace. We can fix whichever kinds or makes—and get the comfort returned to your residence quickly.


What Does the Flashing Light on My Heating System Mean?

Your heating system uses lights to flash code when it is malfunctioning. It also engages these lights to relay it’s running properly.

Regular operation involves:

  • Simultaneous slow flash—heater running properly.
  • Concurrent fast flash—heating system is beginning to call for heat.

If you see a single light blinking slowly and the other going on and off quickly, your furnace might be having a low flame signal. This can happen even when your heating system is heating properly. It indicates the flame sensing rod may have build-up or in the wrong location on the burner. Reach out to us at 724-425-5852 for help.

Here are several other of the most common problems for Lennox furnaces.

Furnace Refuses to Start

Here are many of the light patterns you might notice when your heating system will not or keep operating. Most of these issues need to be repaired by a technician, such as one from Knoechel Heating Company.

  1. Both LED lights are extinguished. This indicates your heating system might not have electricity. Examine the breaker box to make sure the furnace fuse is not flipped. Attempt to reset the fuse if it has moved into the “off” spot. If it immediately flips after a subsequent reset, don’t try to reset it again and get in touch with us us at 724-425-5852.
  2. An individual light is stable and the other is flickering slowly. This implies the flame rollout switch is possibly open. The switch is an important safety guard that aids in avoiding fires and carbon monoxide. You shouldn’t attempt to fix this problem on your own.
  3. An individual light is flashing fast and the other is flashing slowly. This usually signifies power polarity has been transposed. Your furnace could have a wiring problem that calls for expert help from Knoechel Heating Company.
  4. The pair of lights are flashing slowly. This means your furnace’s blower motor likely isn’t running. This component sends hot air from the heater into your residence. We can aid in figuring out what’s wrong with this part.
  5. One light is flickering slowly and the other is flashing fast. This indicates your heater may have low voltage or a short circuit. Get in touch with our specialists at 724-425-5852 for support.
  6. One light is flashing on, on and off while the other blinks on, off, on. This means there may be an issue with your furnace’s motherboard or wiring. Knoechel Heating Company can find the fault and take care of it.
  7. The pair of lights are using alternating slow flickers. This means your HVAC system likely has a flame failure. There may be a problem with its gas supply, gas valve or ignitor control. Reach out to us at 724-425-5852 for support.
  8. A single light flickers slowly while the other remains continuous. This often indicates your heater’s limit switch is malfunctioning. The switch keeps your heating system from getting too hot. Call the experts at Knoechel Heating Company for support.

Furnace Blower Operates But No Warm Air

Here’s what may be broken when you observe your furnace’s blower fan running, but you aren’t receiving any warmth.

  • The pair of lights are showing alternate fast blinks. This means your furnace ignitor might not be in working order. This part ignites energy in your heater to produce heat and should be serviced by a professional from Knoechel Heating Company.

Trust Us for Expert Furnace Repair

When you have to get your heater repaired quickly, depend on the experts at Knoechel Heating Company. Our technicians will fix the problem quickly and have your residence feeling relaxing again soon. Get in touch with us at 724-425-5852 or contact us online to request an appointment now.