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

December 06, 2019

While your Lennox® furnace isn’t able to talk to you, it does have a procedure to communicate a furnace error.

Its control panel has two LED lights that can display a fault code. Depending on the failure, your heater might show continuous or flashing lights.

Although there are some simple furnace adjustments you can complete without an expert, many fixes are best left to HVAC technicians. When your heating system won’t start or give heated air, reach out to JTech Mechanical at 281-231-8768 for skilled furnace repair in Magnolia.

Our specialists will speedily discover and take care of the fault, even if you don’t own a Lennox heater. We can fix all kinds or models—and get the heat returned to your house without delay.


What Does the Blinking Light on My Heating System Mean?

Your heating system uses lights to flash code when it needs to be repaired. It also engages this system to let you know it’s operating properly.

Regular heating consists of:

  • Simultaneous slow flash—heater heating properly.
  • Both lights flash fast—heating system is initiating the call for heat.

If you realize that a solitary light going on and off slowly and the other flashing fast, your heating system may be experiencing a low flame signal. This can take place even when your heater is operating properly. It indicates the flame sensing rod may have build-up or in the wrong area on the burner. Contact us at 281-231-8768 for help.

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

Furnace Won’t Turn On

Here are a few of the light patterns you could notice when your furnace will not or keep running. The bulk of these issues must be taken care of by an expert, like one from JTech Mechanical.

  1. Both LED lights are extinguished. This means your HVAC system might not have power. Find the breaker box to make sure the heater fuse isn’t tripped. You should reset the fuse if it’s in the “off” area. If it immediately trips after a subsequent reset, leave the breaker alone and call us at 281-231-8768.
  2. An individual light is stable and the other is flashing slowly. This signifies the flame rollout switch is probably not working right. The switch is an essential safety device that helps in stopping fires and carbon monoxide. You shouldn’t try to take care of this problem without professional help.
  3. An individual light is flickering quickly and the other is blinking slowly. This typically indicates power polarity has been transposed. Your heating system could have a wiring issue that requires expert support from JTech Mechanical.
  4. All lights are blinking slowly. This indicates your heater’s blower motor possibly isn’t working. This component sends heated air from the furnace into your house. We can help in pinpointing what’s wrong with this piece.
  5. An individual light is blinking slowly and the other is blinking rapidly. This signifies your furnace may have not enough voltage or a short circuit. Reach out to our experts at 281-231-8768 for support.
  6. One light is flashing on, on and off while the other blinks on, off, on. This indicates there might be a problem with your HVAC system’s motherboard or wiring. JTech Mechanical can determine the error and repair it.
  7. Both lights show alternate slow blinks. This indicates your HVAC equipment possibly has a flame issue. There could be an issue with its gas supply, gas valve or ignitor control. Get in touch with us at 281-231-8768 for support.
  8. One light blinks slowly while the other is steady. This often indicates your heater’s limit switch is malfunctioning. The switch prevents your furnace from getting too hot. Call the pros at JTech Mechanical for support.

Heating System Blower Operates But No Warmth

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

  • The pair of lights are giving alternate rapid flashes. This indicates your furnace ignitor may not be working. This component kindles energy in your heating system to make warmth and should be fixed by a technician from JTech Mechanical.

Depend on Us for Professional Furnace Repair

When you have to get your heater repaired without delay, depend on the technicians at JTech Mechanical. Our techs will handle the problem promptly and have your residence feeling comfortable again soon. Get in touch with us at 281-231-8768 or contact us online to get an appointment right away.