Lennox Unit controller

Lennox Error Code 236

Unit controller

What It Means

  • DSI BOARD 1 FLAME LOSS

Causes & actions from Lennox

How it shows
  • M4 alarm code: 236

Direct Spark Ignition board 1 flame loss maximum reached. Board will be locked out for 1 hour. Check gas valve, ignition, and wiring. Lockout may be manually reset by removing power from the control for more than 1 second or removing the thermostat call for heat for more than 1 and less than 20 seconds.

Applicable models & manual sources
Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.

What should you check next?

Continue in ACLogics with guided diagnosis for your equipment and symptoms.

See how guided diagnosis works →