Furnace troubleshooting

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

While your Lennox® furnace cannot chat with you, it possesses 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 heating system might display continuous or flashing lights.

Although there are various simple furnace fixes you can take care of without an expert, the majority of services are best left to the professionals. When your furnace won’t start or put out warmth, reach out to WM J Kraus & Son at 319-229-2318 for professional furnace repair in Keokuk.

Our experts will speedily pinpoint and take care of the malfunction, even if you don’t own a Lennox heater. We can service whichever kinds or models—and get the warmth returned to your house quickly.


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 relay it’s working correctly.

Regular function involves:

  • Both lights flash slowly—furnace operating correctly.
  • Both lights flash fast—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 heating system is running properly. It indicates the flame sensing rod could need to be cleaned or in the incorrect area on the burner. Contact us at 319-229-2318 for assistance.

Here are several other of the most routine issues for Lennox heating systems.

Heater Refuses to Kick On

Here are many of the light patterns you might see when your heater refuses to or keep operating. Most of these problems have to be handled by a professional, for instance from WM J Kraus & Son.

  1. The pair of LED lights are extinguished. This means your heating system might not have power. Check the breaker box to confirm the furnace fuse hasn’t tripped. Attempt to reset the fuse if it’s in the “off” position. If it immediately turns off 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 probably not working right. The switch is a critical safety mechanism that assists in avoiding fires and carbon monoxide. You shouldn’t seek to fix this malfunction without professional help.
  3. One light is flashing rapidly and the other is blinking slowly. This typically means power polarity has been transposed. Your heater might have a wiring fault that requires professional help from WM J Kraus & Son.
  4. All lights are flickering slowly. This means your heating system’s blower motor likely isn’t operating. This part sends warm air from the furnace into your residence. We can aid in pinpointing what’s wrong with this part.
  5. An individual light is blinking slowly and the other is blinking rapidly. This means your heating system may have insufficient voltage or a short circuit. Contact our experts at 319-229-2318 for support.
  6. One light is flashing on, on and off while the other flashes on, off, on. This indicates there might be a fault with your HVAC system’s motherboard or wiring. WM J Kraus & Son can find the issue and handle it.
  7. The duo of lights are using every other slow blinks. This means your heating system 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 assistance.
  8. An individual light blinks slowly while the other is solid. This typically means your HVAC system’s limit switch is malfunctioning. The switch stops your HVAC equipment from getting too hot. Contact the experts at WM J Kraus & Son for help.

Heater Blower Runs But No Warmth

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

  • The pair of lights display every other quick flickers. This indicates your furnace ignitor could not be working. This component lights energy in your HVAC equipment to make warmth and should be fixed by an expert from WM J Kraus & Son.

Trust Us for Expert Furnace Repair

When you need to get your heater repaired quickly, depend on the technicians at WM J Kraus & Son. Our pros will take care of the fault quickly and have your residence feeling cozy again in a short time. Get in touch with us at 319-229-2318 or contact us online to get an appointment right away.

Back To Blog