Boiler does not start at all; no lights or display.

Safety first: Turn off the breaker before opening any electrical junction boxes. Only perform basic visual checks if you are not trained in electrical work.

• 1. Check service switch: Locate the boiler service switch (often near the unit) and ensure it is in the ON position.
• 2. Inspect breaker: At the electrical panel, verify the boiler circuit breaker is not tripped. Reset once if it is.
• 3. Look for indicator lights: Some Weil-McLain controls have power LEDs. If none are lit, the internal fuse or transformer may have failed.
• 4. Examine power cord/wiring: Ensure any plug connection is secure and that visible wiring is not damaged.

If power is present at the boiler but it remains dead, a technician should test and replace the control or transformer as needed.