Unit shows E16; may be associated with very cold inlet water or extreme setpoints.

Safety: Turn OFF power if you suspect overheating; otherwise, adjustments can be made via the control panel.

• Adjust set temperature: Lower the EcoSmart setpoint to a more moderate temperature and test again.
• Increase flow rate: Open the hot tap further to increase flow through the heater, reducing temperature rise per pass.
• Descale unit: If the heater has been in service for years without maintenance and you have hard water, perform a descaling procedure to restore heat transfer efficiency.
• Check sensors: Inspect inlet and outlet thermistors and wiring for damage or loose connections that could cause incorrect readings.
• Retest: After adjustments and maintenance, run the unit again. If E16 persists under normal conditions, sensor or control board calibration may be off and require professional service.