Boiler stops firing and displays 'Soft Lockout' or 'Lockout – Retry' but may automatically reset after a timeout.

Safety first: Turn off power if you remove any covers. If you smell gas, do not attempt to restart the boiler.

• 1. Observe the pattern: Note when the soft lockout occurs (startup, mid-cycle, windy conditions). This helps identify venting or gas supply issues.
• 2. Check vent terminations: Go outside and inspect the Weil-McLain boiler's exhaust and intake terminations. Remove snow, ice, or debris. Ensure clearances per the installation manual.
• 3. Inspect flame sensor: With power off, remove the flame sensor/igniter assembly. Clean the flame rod with fine abrasive pad and reinstall, ensuring proper positioning in the flame.
• 4. Verify condensate drainage: On condensing models, check the condensate trap and drain tubing for blockage or freezing, which can affect combustion and cause flame instability. Clean the trap and ensure proper slope.
• 5. Allow auto reset: Many controls will automatically retry after a soft lockout. After addressing obvious issues, restore power and monitor operation.

Call a technician if: Soft lockouts occur daily or multiple times per day, or if you suspect low gas pressure or combustion tuning issues.