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

December 06, 2019

While your Lennox® HVAC equipment can’t chat with you, it does have a process to tell you about a furnace error.

Its control board has a set of LED lights that can display a fault code. Subject to the problem, your heater may use solid or flashing lights.

Although there are certain basic HVAC repairs you can finish without an expert, most fixes are best handled by HVAC technicians. When your heater will not kick on or deliver heated air, get in touch with Scott Temperature at 785-269-0465 for professional furnace repair in Lawrence.

Our technicians will speedily pinpoint and handle the malfunction, even if you don’t use a Lennox furnace. We can repair all kinds or makes—and get the warmth restored to your home quickly.


What Does the Flashing Light on My Heater Mean?

Your heating system relies on lights to flash code when it isn’t working right. It also uses this system to let you know it’s working like it should.

Regular heating includes:

  • Both lights flash slowly—heating system working correctly.
  • Both lights flash fast—heater is starting to call for heat.

If you notice one light flashing slowly and the other flashing rapidly, your furnace could be having a low flame signal. This can take place even when your heating system is operating correctly. It means the flame sensing rod might have build-up or in the wrong location on the burner. Contact us at 785-269-0465 for help.

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

Furnace Will Not Turn On

Here are many of the light sequences you could see when your heater won’t turn on or keep running. Most of these issues must be repaired by a specialist, such as one from Scott Temperature.

  1. The pair of LED lights are off. This means your furnace might not be receiving power. Find the breaker box to confirm the heating system fuse has not tripped. You should reset the fuse if it is in the “off” spot. If it promptly turns off following a reset, don’t touch the breaker and contact us at 785-269-0465.
  2. A single light is stable and the other is blinking slowly. This shows the flame rollout switch is possibly malfunctioning. The component is a critical safety mechanism that aids in stopping fires and carbon monoxide. You shouldn’t try to fix this fault yourself.
  3. An individual light is flickering fast and the other is blinking slowly. This likely signifies power polarity has been inverted. Your furnace may have a wiring error that calls for specialized help from Scott Temperature.
  4. The pair of lights are blinking slowly. This indicates your heater’s blower motor likely isn’t working. This piece moves hot air from the HVAC system into your space. We can help in figuring out what’s wrong with this piece.
  5. One light is blinking slowly and the other is flickering rapidly. This means your HVAC system could have not enough voltage or a short circuit. Reach out to our professionals at 785-269-0465 for support.
  6. One light is flickering on, on and off while the other flashes on, off, on. This means there could be an error with your HVAC system’s control panel or wiring. Scott Temperature can find the problem and fix it.
  7. Both lights display alternating slow flashes. This means your furnace likely has a flame error. There may be a problem with its gas supply, gas valve or ignitor control. Call us at 785-269-0465 for help.
  8. One light flickers slowly while the other is steady. This often signifies your heater’s limit switch is experiencing an error. The switch keeps your HVAC system from becoming too warm. Call the experts at Scott Temperature for support.

Heater Blower Runs But No Warmth

Here’s what might be wrong when you hear your furnace’s blower fan on, but you aren’t getting any warm air.

  • The duo of lights are showing alternating rapid flashes. This indicates your furnace ignitor may not be working. This component ignites fuel in your HVAC equipment to make heat and should be repaired by a specialist from Scott Temperature.

Depend on Us for Expert Furnace Repair

When you need to have your heating system in working order without delay, depend on the specialists at Scott Temperature. Our technicians will fix the problem right away and have your home feeling comfortable again in no time. Get in touch with us at 785-269-0465 or contact us online to schedule an appointment now.