Unit shows E19 and stops; may be associated with internal water leak detection (if equipped).

Safety first: Turn off power and close water valves before opening the cabinet.

• Inspect for water: Remove the access panel and look for standing water in the base tray or around the heat exchanger.
• Clear condensate drain: Locate the condensate outlet and ensure the hose or pipe is not blocked or kinked. Flush with water if necessary.
• Check internal joints: Examine unions, gaskets, and pipe connections for drips. Tighten or reseal as needed.
• Test leak sensor: If a float or leak sensor is present, ensure it moves freely and is not stuck in the alarm position.
• Dry and reset: Dry the base tray, restore power, and clear the error. If water reappears, further leak investigation is required.