Lennox Flame Loss During Run

Furnace starts but shuts down after 30–60 seconds with no obvious error code at thermostat.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Dirty flame sensor, Intermittent gas valve, Low gas pressure, Poor burner grounding to Lennox chassis

How to Fix / Troubleshooting

Safety: Turn off power and gas before servicing.

  • 1. Clean flame sensor: Remove and clean as previously described.
  • 2. Inspect burner ground: Ensure burner assembly screws are tight and ground wire is secure.

If problem persists, gas pressure and valve operation must be checked by a technician.

Advertisements

Repair Difficulty

Hard 4/5

Required Part

Flame Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements