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Lennox Error Code 3 flashes: Burner failed to light or lost flame (Furnace)

Updated · by Aurora Star Tech Inc.

Lennox error code 3 flashes on a furnace means: Burner failed to light or lost flame. It is also called Lennox diagnostic code 3 flashes.

High severityFurnaceLennox EL195UHNE

Homeowner? What Lennox code 3 flashes means for you

Call a technician Your furnace is reporting: Burner failed to light or lost flame. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
  • Make sure the furnace front door or panel is closed properly; many furnaces will not run with the door switch open.
  • Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the gas valve next to the furnace is open (handle in line with the pipe). Do not force it.
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Lennox error code 3 flashes mean?

The burner did not light, or flame was lost during the heat call.

Applies to: EL195UHNE furnaces with ignition control 103217-03 or 107163-01 (red LED)

Common causes of Lennox code 3 flashes

  • Gas off or low supply pressure
  • Ignitor not glowing
  • Dirty or poorly placed flame sensor

A technician checks these and 3 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Lennox models that use code 3 flashes

EL195UH040NE36BEL195UH060NE36BEL195UH080NE48CEL195UH100NE60C

Other Lennox Furnace codes

CodeMeaning
--Double dashes - zone sensor problem
1 flashLine voltage polarity reversed
2 flashesImproper earth ground
4 flashesLow flame signal
5 flashesWatchguard - ignition retries/recycles exceeded
7 flashesPrimary or secondary limit open
8 flashesRollout switch open
9 flashesPressure switch stays open or drops out on a heat call
10Unknown device detected
10 flashesWatchguard - pressure switch opened 5 times in one heat demand
11Missing device
11 flashesPressure switch stuck closed before inducer starts

All Lennox Furnace error codes →

Lennox code 3 flashes: homeowner questions

What does Lennox code 3 flashes mean?

Burner failed to light or lost flame. The burner did not light, or flame was lost during the heat call.

Is it safe to keep using my furnace with code 3 flashes?

It depends on the cause. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset Lennox code 3 flashes myself?

You can try one reset (power off for 30 seconds, then on). If Lennox code 3 flashes comes back, the cause is still there and a licensed technician should check it.

Who can fix Lennox code 3 flashes near me?

Aurora Star Tech Inc. repairs Lennox furnaces in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean

Troubleshooting guides

Source: Lennox EL195UHNE Unit Information Corp 1801-L1 (rev 04/2024), Table 4 (103217-03) / Table 5 (107163-01) diagnostic codes, p.8-10; p.12-13, 40-45. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency Furnace Repair

647-657-2977