Water heater produces no hot water at any tap; display appears normal and no error code is shown.

Safety: Turn off power at the breaker and close water supply before opening the unit.

• Check display settings: Confirm the set temperature is above inlet temperature and that the unit is not in an ECO or vacation mode that disables heating.
• Verify flow activation: Open a hot tap fully and watch the display. Ensure the flow indicator appears and that the unit shows heating power (kW or bars). If not, inspect and clean the inlet filter and flow sensor.
• Inspect safety limiter: Locate the safety temperature limiter on the heat exchanger and press the manual reset button if present.
• Test heating elements: With power off, measure resistance of each heating element. Replace any open or shorted element with the correct Stiebel Eltron element assembly.
• Professional help: If elements and flow sensor are good but there is still no heating, the control or power board may be faulty and should be diagnosed by a technician.