Furnace troubleshooting

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

While your Lennox® heating system isn’t able to speak to you, it does have a process to tell you about a furnace error.

Its control panel has double LED lights that can display a fault code. Subject to the problem, your furnace may use steady or flashing lights.

Although there are various simple HVAC adjustments you can take care of yourself, many tasks are best left to HVAC technicians. When your furnace won’t turn on or deliver warmth, reach out to D & D Heating & AC at 720-316-1401 for skilled furnace repair in Brighton.

Our technicians will quickly detect and take care of the issue, even if you don’t own a Lennox furnace. We can fix whichever types or models—and get the warmth returned to your home without delay.


What Does the Flickering Light on My Heating System Mean?

Your heating system relies on lights to flash code when it requires repairs. It also engages this setup to relay it’s heating like it should.

Normal operation includes:

  • Concurrent slow flash—heater working properly.
  • Both lights flash fast—furnace is starting to call for heat.

If you see a single light going on and off slowly and the other flashing fast, your furnace may be experiencing a low flame signal. This can happen even when your heater is running like it should. It signifies the flame sensing rod may be dirty or in the bad location on the burner. Call us at 720-316-1401 for assistance.

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

Furnace Refuses to Turn On

Here are a few of the light patterns you might notice when your furnace won’t turn on or keep heating. The majority of these errors have to be taken care of by a technician, like one from D & D Heating & AC.

  1. Both LED lights are off. This indicates your heating system might not be receiving power. Find the breaker box to make sure the heating system fuse has not flipped. Attempt to reset the fuse if it’s in the “off” area. If it immediately flips after a subsequent reset, don’t try to reset it again and get in touch with us us at 720-316-1401.
  2. A single light is unchanging and the other is flickering slowly. This shows the flame rollout switch is may be malfunctioning. The part is a critical safety mechanism that aids in preventing fires and carbon monoxide. You shouldn’t attempt to fix this fault yourself.
  3. One light is flickering quickly and the other is flickering slowly. This likely means power polarity has been inverted. Your heating system may have a wiring fault that needs professional help from D & D Heating & AC.
  4. The duo of lights are blinking slowly. This indicates your furnace’s blower motor probably isn’t running. This piece moves hot air from the heating system into your space. We can assist in figuring out what’s causing a problem with this piece.
  5. A single light is flashing slowly and the other is blinking rapidly. This means your heating system might have insufficient voltage or a short circuit. Get in touch with our technicians at 720-316-1401 for support.
  6. One light is blinking on, on and off while the other blinks on, off, on. This means there might be an error with your heater’s control panel or wiring. D & D Heating & AC can find the problem and handle it.
  7. The pair of lights are using every other slow flickers. This signifies your heating system may have a flame problem. There could be trouble with its gas supply, gas valve or ignitor control. Get in touch with us at 720-316-1401 for support.
  8. One light flashes slowly while the other stays steady. This typically means your heater’s limit switch is experiencing an error. The switch keeps your HVAC equipment from overheating. Reach out to the specialists at D & D Heating & AC for help.

Heater Blower Works But No Warm Air

Here’s what might be at fault when you notice your furnace’s blower fan working, but you aren’t receiving any heated air.

  • The duo of lights are giving alternating quick flickers. This means your furnace ignitor might not be working. This piece ignites fuel in your heater to create warmth and should be fixed by a technician from D & D Heating & AC.

Turn to Us for Professional Furnace Repair

When you need to get your HVAC equipment fixed quickly, turn to the specialists at D & D Heating & AC. Our technicians will fix the error without delay and have your home feeling cozy again soon. Get in touch with us at 720-316-1401 or contact us online to request an appointment right away.

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