Furnace troubleshooting

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

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

Its control board has twin LED lights that can display a fault code. Depending on the problem, your furnace may display continuous or flashing lights.

Though there are a few elementary heating adjustments you can finish yourself, many services are best left to the professionals. When your heater will not turn on or give heated air, reach out to B & G HVAC at 641-323-1210 for expert furnace repair in Marshalltown.

Our specialists will speedily identify and fix the malfunction, even if you don’t use a Lennox heater. We can fix all types or makes—and get the warmth returned to your house quickly.


What Does the Flashing Light on My Furnace Mean?

Your heater depends on lights to flash code when it is malfunctioning. It also works this system to tell you it’s running properly.

Regular heating involves:

  • Simultaneous slow flash—furnace working like it should.
  • Simultaneous fast flash—furnace is beginning to call for heat.

If you realize that a single light flashing slowly and the other going on and off fast, your heating system might have a low flame signal. This can occur even when your heater is heating like it should. It means the flame sensing rod could be dirty or in the bad spot on the burner. Call us at 641-323-1210 for help.

Here are a few other of the most common issues for Lennox furnaces.

Furnace Will Not Kick On

Here are a few of the light sequences you might notice when your heat won’t turn on or keep heating. The majority of these problems need to be taken care of by a technician, such as one from B & G HVAC.

  1. The pair of LED lights are off. This means your heater might not be receiving power. Find the breaker box to confirm the heater fuse isn’t flipped. Try resetting the fuse if it is in the “off” position. If it promptly trips after you reset it, don’t try to reset it again and contact us at 641-323-1210.
  2. An individual light is solid and the other is blinking slowly. This shows the flame rollout switch is likely open. The component is a critical safety device that aids in preventing fires and carbon monoxide. You shouldn’t try to repair this problem yourself.
  3. A single light is blinking fast and the other is flashing slowly. This typically signifies power polarity has been reversed. Your heater might have a wiring issue that needs professional support from B & G HVAC.
  4. Both lights are flashing slowly. This means your heating system’s blower motor likely isn’t running. This component sends warm air from the heater into your rooms. We can aid in pinpointing what’s causing an issue with this piece.
  5. A single light is flashing slowly and the other is flashing rapidly. This means your furnace might have insufficient voltage or a short circuit. Reach out to our professionals at 641-323-1210 for support.
  6. One light is blinking on, on and off while the other flickers on, off, on. This indicates there may be a problem with your HVAC system’s control board or wiring. B & G HVAC can pinpoint the issue and handle it.
  7. The duo of lights display every other slow flashes. This indicates your heater possibly has a flame error. There may be a problem with its gas supply, gas valve or ignitor control. Contact us at 641-323-1210 for help.
  8. One light flashes slowly while the other remains steady. This typically indicates your heating system’s limit switch is malfunctioning. The switch prevents your heater from becoming too warm. Reach out to the specialists at B & G HVAC for help.

Heating System Blower Works But No Heat

Here’s what may be wrong when you observe your heating system’s blower fan working, but you aren’t receiving any warm air.

  • Both lights display alternate fast flashes. This indicates your furnace ignitor could be broken. This component ignites gas in your heating system to make warmth and should be fixed by an expert from B & G HVAC.

Depend on Us for Skilled Furnace Repair

When you need to get your heater fixed quickly, turn to the experts at B & G HVAC. Our pros will take care of the error right away and have your rooms feeling comfortable again in a short time. Contact us at 641-323-1210 or contact us online to get an appointment today.

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