Dishwasher shows H1; water does not heat properly and cycles may be extended.

Safety first: Turn off power at the breaker before testing the heater.

• 1. Check water temperature: Ensure the hot water supply to the dishwasher is at least 49–60°C (120–140°F). Very cold inlet water can cause heating timeouts.
• 2. Inspect heater for scale: Access the heater and look for heavy limescale buildup. In hard water areas, this can significantly reduce heating efficiency.
• 3. Test heater resistance: Measure the heater's resistance and compare to Haier specifications. A value drifting high may indicate a weakening element.
• 4. Check NTC sensor: Verify the temperature sensor is reading correctly; a sensor that reads too low will cause extended heating.
• 5. Replace faulty parts: Replace the heater assembly or NTC sensor as needed. Consider using dishwasher-safe descaler periodically to reduce scale buildup.

Warning: Do not chip scale off the heater with metal tools; you may damage the element.