HVAC Code Lookup

Lennox Furnace Code E270

Soft lockout

Soft lockout. The furnace used up its maximum number of ignition retries and never sensed any flame current, so it stopped trying to light.

Manual wording: “Soft lockout - Exceeded maximum number of retries. No flame current sensed. Check for proper gas flow. Ensure that ignitor is lighting burner. Check flame sensor current.”

Documented for: EL296UHE and SLP98UHV series

Likely causes, most common first

  1. No gas supply to the furnace, or the manual gas valve is closed
  2. Ignitor not lighting the burners
  3. Flame sensor not proving the flame
  4. Gas pressure too low

What you can safely check yourself

  • Check that other gas appliances in the house are working, which tells you whether gas is being delivered
  • Check that the furnace door is fully seated
  • Turn the furnace power switch off for 30 seconds and back on once, one time only

When to call a technician

The manual's action is to check gas flow, confirm the ignitor is lighting the burner and check flame sensor current. Stop resetting the furnace and have a technician find out why it will not light.

A Lennox furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Lennox codes