Furnace troubleshooting

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

While your Lennox® furnace cannot speak to you, it has a method to get your attention when there’s a furnace error.

Its control board has twin LED lights that can share a fault code. Depending on the malfunction, your heater could show continuous or flashing lights.

Though there are some simple furnace fixes you can take care of on your own, the majority of tasks are best left to the professionals. When your furnace won’t start or put out warmth, call WM J Kraus & Son at 319-229-2318 for professional furnace repair in Keokuk.

Our experts will quickly pinpoint and take care of the malfunction, even if you don’t use a Lennox heating system. We can service whichever types or makes—and get the comfort returned to your residence without delay.


What Does the Flickering Light on My Heater Mean?

Your furnace relies on lights to flash code when it requires repairs. It also works these lights to let you know it’s working correctly.

Regular function involves:

  • Both lights flash slowly—heater operating correctly.
  • Simultaneous fast flash—heater is starting to call for heat.

If you see a lone light going on and off slowly and the other flashing rapidly, your furnace might have a low flame signal. This can happen even when your heater is running properly. It signifies the flame sensing rod could have build-up or in the wrong area on the burner. Contact us at 319-229-2318 for assistance.

Here are some of the most typical faults for Lennox heating systems.

Heater Refuses to Start

Here are a few of the light patterns you could see when your heater will not or keep operating. The bulk of these issues have to be handled by an expert, for instance from WM J Kraus & Son.

  1. The pair of LED lights aren’t lit. This means your heating system might not have power. Find the breaker box to confirm the furnace fuse hasn’t tripped. Attempt to reset the fuse if it is in the “off” position. If it immediately flips after you reset it, leave the breaker alone and call us at 319-229-2318.
  2. An individual light is solid and the other is blinking slowly. This implies the flame rollout switch is likely not working right. The switch is an essential safety mechanism that aids in stopping fires and carbon monoxide. You shouldn’t seek to fix this problem without professional help.
  3. One light is flashing rapidly and the other is flickering slowly. This usually means power polarity has been transposed. Your heater might have a wiring error that requires professional support from WM J Kraus & Son.
  4. All lights are flickering slowly. This means your heating system’s blower motor possibly isn’t operating. This part sends warm air from the furnace into your residence. We can assist in pinpointing what’s wrong with this part.
  5. An individual light is flickering slowly and the other is flickering fast. This means your heating system may have insufficient voltage or a short circuit. Contact our experts at 319-229-2318 for assistance.
  6. One light is flashing on, on and off while the other flashes on, off, on. This indicates there could be a fault with your HVAC system’s control panel or wiring. WM J Kraus & Son can find the fault and handle it.
  7. The duo of lights display alternate slow flickers. This means your heater possibly has a flame issue. There might be a problem with its gas supply, gas valve or ignitor control. Reach out to us at 319-229-2318 for support.
  8. An individual light blinks slowly while the other is solid. This typically means your HVAC system’s limit switch is open. The switch stops your HVAC equipment from getting too hot. Contact the professionals at WM J Kraus & Son for support.

Heater Blower Runs But No Warm Air

Here’s what could be broken when you notice your furnace’s blower fan working, but you aren’t gaining any heat.

  • The duo of lights display every other quick blinks. This signifies your furnace ignitor might not be working. This piece lights energy in your HVAC equipment to create warm air and should be fixed by an expert from WM J Kraus & Son.

Trust Us for Expert Furnace Repair

When you need to have your heater in working order quickly, trust the technicians at WM J Kraus & Son. Our techs will take care of the fault quickly and have your house feeling cozy again soon. Get in touch with us at 319-229-2318 or contact us online to get an appointment right away.

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