Boiler frequently locks out and must be manually reset, but no specific code is displayed or retained.

Safety first: Turn off power before tightening connections or removing panels.

• Step 1 – Record conditions: Note when lockouts occur (windy days, long runs, specific zones). This helps identify patterns.
• Step 2 – Tighten connections: Inspect and snug all low-voltage and line-voltage connections at the control board, gas valve, pressure switch, and sensors.
• Step 3 – Clean flame sensor: Even if not coded, a weak flame signal can cause intermittent lockouts. Clean the flame sensor rod as described in other entries.
• Step 4 – Check venting and intake: Ensure vent and intake terminations are clear and properly installed. Wind effects can cause intermittent pressure switch trips.
• Step 5 – Professional diagnostics: If the problem persists, a technician should monitor flame signal strength, pressure switch operation, and control board behavior during operation.

Note: Repeated manual resets without finding the cause can mask a developing safety issue.