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

December 06, 2019

While your Lennox® furnace cannot speak to you, it possesses a way to communicate a furnace error.

Its motherboard has a set of LED lights that can share a fault code. Subject to the failure, your heating system may show solid or flashing lights.

Though there are certain simple furnace fixes you can complete yourself, the majority of services are best handled by experts. When your heating system refuses to kick on or deliver warm air, call Tokay Heating and Air Conditioning at 209-257-3156 for skilled furnace repair in Lodi.

Our technicians will speedily determine and take care of the problem, even if you don’t own a Lennox furnace. We can fix all types or configuration—and get the warmth restored to your residence without delay.


What Does the Flashing Light on My Heater Mean?

Your furnace depends on lights to flash code when it isn’t working right. It also engages this system to tell you it’s operating correctly.

Regular operation consists of:

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

If you realize that one light going on and off slowly and the other blinking fast, your furnace might be having a low flame signal. This can occur even when your furnace is working correctly. It indicates the flame sensing rod might have build-up or in the incorrect location on the burner. Reach out to us at 209-257-3156 for assistance.

Here are several other of the most common faults for Lennox HVAC systems.

Heating System Will Not Start

Here are many of the light sequences you might notice when your heating system refuses to or keep running. Most of these problems have to be repaired by a specialist, such as one from Tokay Heating and Air Conditioning.

  1. Both LED lights aren’t lit. This means your furnace might not be receiving power. Look at the breaker box to make sure the heater fuse is not flipped. Try resetting the fuse if it has moved into the “off” area. If it immediately flips after a subsequent reset, leave the breaker alone and get in touch with us us at 209-257-3156.
  2. A single light is unchanging and the other is blinking slowly. This implies the flame rollout switch is may be malfunctioning. The component is an essential safety mechanism that assists in avoiding fires and carbon monoxide. You shouldn’t seek to handle this fault yourself.
  3. An individual light is flickering fast and the other is flickering slowly. This usually means power polarity has been inverted. Your heater might have a wiring fault that requires specialized help from Tokay Heating and Air Conditioning.
  4. The pair of lights are blinking slowly. This indicates your heater’s blower motor likely isn’t running. This component distributes hot air from the HVAC system into your residence. We can help in figuring out what’s causing a problem with this piece.
  5. A single light is blinking slowly and the other is flickering fast. This signifies your heater might have insufficient voltage or a short circuit. Reach out to our professionals at 209-257-3156 for assistance.
  6. One light is blinking on, on and off while the other flashes on, off, on. This signifies there could be an issue with your heater’s motherboard or wiring. Tokay Heating and Air Conditioning can locate the issue and handle it.
  7. The duo of lights show alternating slow flashes. This indicates your furnace possibly has a flame issue. There may be a problem with its gas supply, gas valve or ignitor control. Call us at 209-257-3156 for support.
  8. A single light flickers slowly while the other is steady. This often means your HVAC equipment’s limit switch is open. The switch keeps your heater from getting too hot. Contact the experts at Tokay Heating and Air Conditioning for assistance.

Furnace Blower Runs But No Warm Air

Here’s what could be at fault when you notice your furnace’s blower fan running, but you aren’t getting any warm air.

  • The duo of lights are showing alternating fast flashes. This signifies your furnace ignitor might not be working. This piece lights fuel in your heating system to produce warmth and should be serviced by a technician from Tokay Heating and Air Conditioning.

Turn to Us for Professional Furnace Repair

When you have to have your furnace fixed quickly, turn to the specialists at Tokay Heating and Air Conditioning. Our technicians will handle the fault without delay and have your house feeling cozy again soon. Reach out to us at 209-257-3156 or contact us online to request an appointment right away.