Furnace troubleshooting

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

While your Lennox® HVAC equipment cannot speak to you, it does have a process to communicate a furnace error.

Its motherboard has twin LED lights that can show a fault code. Based on the fault, your heater could show solid or flashing lights.

Although there are certain elementary furnace repairs you can finish on your own, most services are best handled by experts. When your heater won’t start or put out warmth, get in touch with Street Heating and Cooling at 605-206-3915 for expert furnace repair in Rapid City.

Our technicians will rapidly pinpoint and handle the breakdown, even if you don’t have a Lennox heating system. We can repair any kinds or makes—and get the heat returned to your house fast.


What Does the Blinking Light on My Furnace Mean?

Your furnace relies on lights to flash code when it needs to be repaired. It also works these lights to tell you it’s running correctly.

Normal heating consists of:

  • Concurrent slow flash—furnace running correctly.
  • Both lights flash fast—heater is initiating the call for heat.

If you realize that one light blinking slowly and the other flashing quickly, your heating system may be experiencing a low flame signal. This can occur even when your heating system is heating correctly. It means the flame sensing rod might have build-up or in the wrong spot on the burner. Call us at 605-206-3915 for assistance.

Here are some of the most typical problems for Lennox furnaces.

Furnace Will Not Start

Here are many of the light patterns you might see when your heater won’t turn on or stay on. The bulk of these issues must be fixed by a professional, for instance from Street Heating and Cooling.

  1. The duo of LED lights aren’t lit. This indicates your furnace might not have power. Examine the breaker box to confirm the heating system fuse isn’t triggered. Try resetting the fuse if it is in the “off” area. If it instantly trips after you reset it, leave the breaker alone and call us at 605-206-3915.
  2. One light is stable and the other is flashing slowly. This signifies the flame rollout switch is likely not working right. The part is an essential safety device that assists in stopping fires and carbon monoxide. You shouldn’t try to take care of this fault on your own.
  3. One light is flickering fast and the other is flashing slowly. This likely indicates power polarity has been inverted. Your furnace could have a wiring problem that requires professional aid from Street Heating and Cooling.
  4. Both lights are flashing slowly. This means your heater’s blower motor possibly isn’t running. This component sends warm air from the furnace into your residence. We can assist in determining what’s causing an issue with this part.
  5. One light is blinking slowly and the other is flashing rapidly. This means your heating system could have not enough voltage or a short circuit. Contact our professionals at 605-206-3915 for assistance.
  6. One light is blinking on, on and off while the other flickers on, off, on. This means there could be a problem with your heater’s control board or wiring. Street Heating and Cooling can pinpoint the error and take care of it.
  7. The duo of lights are using every other slow flashes. This signifies your heater likely has a flame problem. There could be an issue with its gas supply, gas valve or ignitor control. Call us at 605-206-3915 for assistance.
  8. One light blinks slowly while the other remains continuous. This often indicates your furnace’s limit switch is not working. The switch stops your furnace from becoming too warm. Reach out to the pros at Street Heating and Cooling for help.

Heating System Blower Works But No Warm Air

Here’s what may be wrong when you hear your heating equipment’s blower fan on, but you aren’t getting any heat.

  • The duo of lights are showing alternate quick blinks. This signifies your furnace ignitor could not be in working order. This part kindles gas in your HVAC equipment to produce warmth and should be fixed by a specialist from Street Heating and Cooling.

Turn to Us for Skilled Furnace Repair

When you have to have your furnace repaired without delay, turn to the experts at Street Heating and Cooling. Our techs will fix the issue promptly and have your house feeling comfortable again soon. Reach out to us at 605-206-3915 or contact us online to get an appointment right away.

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