Weil-McLain water heater will not start at all; no lights or display on the control.

Safety first: Turn off the breaker before opening any electrical compartments. Use a non-contact voltage tester if available.

• Check breaker and switch: Verify the circuit breaker feeding the water heater is not tripped. Ensure any local service switch is in the ON position.
• Inspect power connections: Remove the electrical junction box cover on the heater and check for loose wire nuts or burned connections.
• Check fuses and transformer: Some Weil-McLain controls use low-voltage transformers and fuses. Inspect and replace blown fuses only with identical ratings.
• Control replacement: If proper power is present at the control but it remains dead, the control module or transformer may need replacement by a qualified technician.