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

December 06, 2019

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

Its motherboard has double LED lights that can show a fault code. Depending on the malfunction, your heater might display continuous or flashing lights.

While there are various basic furnace adjustments you can do without an expert, most tasks are best handled by the professionals. When your heater won’t turn on or deliver warmth, get in touch with Woody's Sudden Service Inc at 703-278-2036 for experienced furnace repair in Manassas.

Our technicians will swiftly identify and handle the fault, even if you don’t have a Lennox furnace. We can service all types or configuration—and get the comfort returned to your residence fast.


What Does the Flickering Light on My Heating System Mean?

Your heating system relies on lights to flash code when it needs to be repaired. It also engages this system to relay it’s operating like it should.

Correct operation involves:

  • Concurrent slow flash—heating system working correctly.
  • Concurrent fast flash—furnace is initiating the call for heat.

If you notice a lone light going on and off slowly and the other flashing quickly, your heater might have a low flame signal. This can take place even when your heating system is heating correctly. It means the flame sensing rod may be dirty or in the bad location on the burner. Call us at 703-278-2036 for help.

Here are several other of the most typical problems for Lennox heaters.

Heater Won’t Start

Here are many of the light arrangements you could see when your furnace will not or keep running. The majority of these errors need to be fixed by a technician, such as one from Woody's Sudden Service Inc.

  1. Both LED lights aren’t lit. This indicates your furnace might not have power. Look at the breaker box to make sure the furnace fuse isn’t flipped. You should reset the fuse if it is in the “off” spot. If it instantly turns off following a reset, don’t try to reset it again and get in touch with us us at 703-278-2036.
  2. An individual light is unchanging and the other is flickering slowly. This means the flame rollout switch is may be open. The part is an important safety mechanism that aids in preventing fires and carbon monoxide. You shouldn’t try to handle this malfunction without professional help.
  3. A single light is flashing quickly and the other is flashing slowly. This often indicates power polarity has been reversed. Your heater could have a wiring problem that requires expert help from Woody's Sudden Service Inc.
  4. The pair of lights are flashing slowly. This signifies your heating system’s blower motor possibly isn’t running. This piece moves warm air from the furnace into your house. We can assist in determining what’s causing a problem with this component.
  5. A single light is blinking slowly and the other is flashing quickly. This means your heater may have low voltage or a short circuit. Get in touch with our experts at 703-278-2036 for assistance.
  6. One light is flashing on, on and off while the other flashes on, off, on. This means there could be trouble with your furnace’s motherboard or wiring. Woody's Sudden Service Inc can locate the error and handle it.
  7. The duo of lights display alternating slow blinks. This means your HVAC equipment may have a flame problem. There might be an issue with its gas supply, gas valve or ignitor control. Call us at 703-278-2036 for support.
  8. One light blinks slowly while the other remains solid. This typically signifies your heater’s limit switch is malfunctioning. The switch keeps your heater from overheating. Reach out to the pros at Woody's Sudden Service Inc for help.

Heating System Blower Operates But No Warmth

Here’s what might be wrong when you notice your heating system’s blower fan working, but you aren’t receiving any heated air.

  • The pair of lights are showing alternate fast flickers. This signifies your furnace ignitor may not be in working order. This part ignites energy in your heating system to make heat and should be fixed by a specialist from Woody's Sudden Service Inc.

Depend on Us for Professional Furnace Repair

When you have to get your heating system repaired quickly, turn to the specialists at Woody's Sudden Service Inc. Our technicians will fix the fault without delay and have your rooms feeling comfortable again in no time. Get in touch with us at 703-278-2036 or contact us online to get an appointment now.