Heater shows E16; may indicate low voltage or power supply issues to the control.

Safety: Turn off power at the breaker before opening the electrical junction box.

Steps:

• Check breaker and wiring: Confirm the heater is on a dedicated circuit sized per Lochinvar specifications. Inspect the junction box for loose wire nuts or burned connections.
• Measure voltage (advanced): With a multimeter and proper precautions, verify that line voltage at the heater matches the nameplate rating (typically 120V or 240V). Significant drops when the heater starts indicate wiring or supply issues.
• Inspect transformer: If equipped with a low-voltage transformer, check for overheating or buzzing. A technician can test secondary voltage to confirm operation.

Persistent E16 requires an electrician or technician to correct wiring or replace the transformer/control board.