Furnace troubleshooting

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

While your Lennox® furnace cannot chat with you, it has a way to communicate a furnace error.

Its control panel has a set of LED lights that can display a fault code. Based on the fault, your furnace may display solid or flashing lights.

Although there are certain elementary furnace repairs you can do without an expert, most services are best taken care of by HVAC technicians. When your heater refuses to kick on or put out warm air, reach out to Controlled Comfort HVAC Inc at 224-699-9229 for experienced furnace repair in Carpentersville.

Our specialists will swiftly discover and repair the breakdown, even if you don’t have a Lennox furnace. We can repair whichever brands or configuration—and get the heat restored to your home without delay.


What Does the Blinking Light on My Furnace Mean?

Your furnace relies on lights to flash code when it is malfunctioning. It also engages this system to tell you it’s working correctly.

Correct function involves:

  • Concurrent slow flash—furnace operating properly.
  • Simultaneous fast flash—heating system is beginning to call for heat.

If you notice a solitary light blinking slowly and the other flashing rapidly, your heater might be experiencing a low flame signal. This can happen even when your heater is running correctly. It indicates the flame sensing rod could be dirty or in the incorrect area on the burner. Call us at 224-699-9229 for support.

Here are a few other of the most typical errors for Lennox HVAC systems.

Furnace Will Not Kick On

Here are many of the light sequences you might notice when your heater won’t turn on or keep heating. Most of these errors must be taken care of by a specialist, for instance from Controlled Comfort HVAC Inc.

  1. Both LED lights are extinguished. This signifies your heater might not be receiving power. Find the breaker box to make sure the furnace fuse hasn’t flipped. Attempt to reset the fuse if it has moved into the “off” position. If it rapidly turns off following a reset, leave the breaker alone and call us at 224-699-9229.
  2. A single light is continuous and the other is flickering slowly. This means the flame rollout switch is likely malfunctioning. The component is an essential safety tool that aids in stopping fires and carbon monoxide. You shouldn’t seek to handle this issue yourself.
  3. One light is flashing fast and the other is flashing slowly. This likely signifies power polarity has been inverted. Your heater could have a wiring fault that calls for professional assistance from Controlled Comfort HVAC Inc.
  4. The pair of lights are flickering slowly. This means your furnace’s blower motor likely isn’t running. This component circulates hot air from the furnace into your rooms. We can aid in figuring out what’s wrong with this piece.
  5. An individual light is blinking slowly and the other is blinking rapidly. This means your heating system might have insufficient voltage or a short circuit. Reach out to our technicians at 224-699-9229 for support.
  6. One light is flickering on, on and off while the other flashes on, off, on. This indicates there could be trouble with your furnace’s motherboard or wiring. Controlled Comfort HVAC Inc can pinpoint the fault and fix it.
  7. The duo of lights are using every other slow flickers. This means your HVAC system possibly has a flame problem. There might be an issue with its gas supply, gas valve or ignitor control. Call us at 224-699-9229 for support.
  8. A single light flashes slowly while the other remains continuous. This typically signifies your furnace’s limit switch is malfunctioning. The switch stops your heater from getting too hot. Call the specialists at Controlled Comfort HVAC Inc for help.

Heating System Blower Operates But No Warmth

Here’s what might be broken when you observe your heater’s blower fan running, but you aren’t getting any warm air.

  • The pair of lights are giving alternating quick flickers. This signifies your furnace ignitor could not be in working order. This piece ignites energy in your furnace to make warm air and should be fixed by a specialist from Controlled Comfort HVAC Inc.

Turn to Us for Professional Furnace Repair

When you need to have your heating system in working order without delay, turn to the professionals at Controlled Comfort HVAC Inc. Our technicians will handle the fault without delay and have your space feeling cozy again in a short time. Call us at 224-699-9229 or contact us online to schedule an appointment right away.

Back To Blog