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

December 06, 2019

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

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

Although there are various basic heating repairs you can finish without an expert, the majority of fixes are best left to HVAC technicians. When your heater will not start or deliver warmth, reach out to Jent Mechanical LLC at 937-845-1111 for experienced furnace repair in Dayton.

Our technicians will speedily determine and repair the malfunction, even if you don’t own a Lennox furnace. We can repair all types or models—and get the warmth returned to your residence quickly.


What Does the Flashing Light on My Heater Mean?

Your furnace depends on lights to flash code when it needs to be repaired. It also works this system to let you know it’s running correctly.

Normal operation consists of:

  • Concurrent slow flash—heater operating properly.
  • Concurrent fast flash—heater is starting to call for heat.

If you realize that a lone light flashing slowly and the other flashing fast, your furnace could have a low flame signal. This can happen even when your heating system is running properly. It signifies the flame sensing rod may be dirty or in the incorrect area on the burner. Call us at 937-845-1111 for help.

Here are some of the most typical faults for Lennox heaters.

Heater Will Not Start

Here are some of the light patterns you could observe when your furnace will not or keep operating. Most of these problems must be taken care of by an expert, for instance from Jent Mechanical LLC.

  1. The duo of LED lights aren’t lit. This indicates your HVAC system might not have electricity. Check the breaker box to make sure the furnace fuse isn’t triggered. Attempt to reset the fuse if it is in the “off” spot. If it promptly turns off after a subsequent reset, don’t touch the breaker and call us at 937-845-1111.
  2. One light is continuous and the other is flashing slowly. This means the flame rollout switch is likely not working right. The switch is a critical safety guard that helps in preventing fires and carbon monoxide. You shouldn’t attempt to take care of this malfunction on your own.
  3. One light is flickering quickly and the other is flashing slowly. This typically signifies power polarity has been transposed. Your heater might have a wiring fault that calls for specialized support from Jent Mechanical LLC.
  4. The duo of lights are flickering slowly. This indicates your heating system’s blower motor probably isn’t working. This part circulates warm air from the HVAC system into your home. We can aid in pinpointing what’s wrong with this component.
  5. One light is blinking slowly and the other is flashing quickly. This signifies your heater could have not enough voltage or a short circuit. Reach out to our technicians at 937-845-1111 for help.
  6. One light is blinking on, on and off while the other blinks on, off, on. This means there could be a malfunction with your heating system’s motherboard or wiring. Jent Mechanical LLC can pinpoint the error and repair it.
  7. The pair of lights are using every other slow flashes. This means your heating system likely has a flame failure. There could be trouble with its gas supply, gas valve or ignitor control. Reach out to us at 937-845-1111 for assistance.
  8. A single light flashes slowly while the other remains solid. This usually signifies your furnace’s limit switch is malfunctioning. The switch prevents your heater from getting too hot. Reach out to the experts at Jent Mechanical LLC for help.

Heater Blower Operates But No Heat

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

  • Both lights are giving alternate fast blinks. This indicates your furnace ignitor might not be working. This component lights gas in your heating system to make warmth and should be fixed by an expert from Jent Mechanical LLC.

Depend on Us for Expert Furnace Repair

When you need to have your heater in working order quickly, turn to the specialists at Jent Mechanical LLC. Our pros will handle the fault without delay and have your space feeling relaxing again in no time. Contact us at 937-845-1111 or contact us online to get an appointment right away.