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

December 06, 2019

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

Its control panel has twin LED lights that can display a fault code. Depending on the problem, your heating system could use continuous or flashing lights.

Though there are some elementary heating fixes you can take care of yourself, most tasks are best left to experts. When your heater refuses to turn on or provide heat, get in touch with Controlled Comfort HVAC Inc at 224-412-8308 for skilled furnace repair in Carpentersville.

Our technicians will rapidly determine and repair the fault, even if you don’t own a Lennox furnace. We can repair whichever brands or configuration—and get the warmth returned to your home fast.


What Does the Flashing Light on My Furnace Mean?

Your heater uses lights to flash code when it isn’t working right. It also works these lights to tell you it’s heating properly.

Normal heating includes:

  • Simultaneous slow flash—heating system heating like it should.
  • Both lights flash fast—heating system is initiating the call for heat.

If you realize that one light blinking slowly and the other blinking rapidly, your furnace could have a low flame signal. This can occur even when your heater is running properly. It means the flame sensing rod might be dirty or in the wrong spot on the burner. Contact us at 224-412-8308 for help.

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

Heating System Won’t Start

Here are some of the light patterns you could see when your furnace won’t turn on or stay on. The majority of these errors have to be taken care of by a specialist, for instance from Controlled Comfort HVAC Inc.

  1. The duo of LED lights are off. This indicates your heater might not be receiving power. Go to the breaker box to confirm the heater fuse hasn’t tripped. Try resetting the fuse if it is in the “off” spot. If it promptly flips following a reset, leave the breaker alone and get in touch with us us at 224-412-8308.
  2. An individual light is continuous and the other is flickering slowly. This means the flame rollout switch is may be not working right. The switch is an important safety mechanism that assists in preventing fires and carbon monoxide. You shouldn’t attempt to take care of this malfunction on your own.
  3. One light is blinking quickly and the other is flashing slowly. This typically means power polarity has been transposed. Your heating system may have a wiring issue that calls for expert assistance from Controlled Comfort HVAC Inc.
  4. All lights are blinking slowly. This indicates your heater’s blower motor possibly isn’t operating. This piece moves warm air from the HVAC system into your rooms. We can aid in figuring out what’s wrong with this component.
  5. One light is flickering slowly and the other is flashing rapidly. This signifies your heater might have insufficient voltage or a short circuit. Reach out to our specialists at 224-412-8308 for assistance.
  6. One light is blinking on, on and off while the other blinks on, off, on. This means there could be an issue with your HVAC system’s motherboard or wiring. Controlled Comfort HVAC Inc can determine the error and fix it.
  7. The duo of lights show every other slow flickers. This signifies your heater likely has a flame failure. There might be trouble with its gas supply, gas valve or ignitor control. Get in touch with us at 224-412-8308 for help.
  8. An individual light flashes slowly while the other stays solid. This usually indicates your furnace’s limit switch is not working. The switch prevents your heater from overheating. Get in touch with the professionals at Controlled Comfort HVAC Inc for assistance.

Heating System Blower Works But No Warm Air

Here’s what may be broken when you notice your furnace’s blower fan working, but you aren’t receiving any heated air.

  • The duo of lights are showing alternate rapid blinks. This signifies your furnace ignitor could be broken. This piece kindles fuel in your furnace to make heat and should be serviced by a specialist from Controlled Comfort HVAC Inc.

Depend on Us for Expert Furnace Repair

When you need to get your furnace in working order fast, depend on the technicians at Controlled Comfort HVAC Inc. Our technicians will take care of the error right away and have your residence feeling relaxing again soon. Reach out to us at 224-412-8308 or contact us online to request an appointment today.