Water heater produces no hot water at all, but no error code is displayed

Safety: Turn off power and close water valves before removing any covers or filters.

• 1. Check taps and valves: Ensure the main cold water inlet valve to the Beretta heater is fully open and that hot taps in the house are open when testing.
• 2. Verify display demand: When a hot tap is opened, many Beretta models show a tap symbol or DHW demand indicator. If this does not appear, the flow sensor may not be detecting flow.
• 3. Clean inlet filter: Close the cold inlet valve. Remove and clean the inlet filter screen at the heater's cold water connection. Rinse out debris and reinstall.
• 4. Flow sensor check (technician): A professional should remove and inspect the DHW flow sensor or turbine for limescale and verify its electrical output to the PCB.
• 5. DHW NTC check: If the heater starts but shuts down quickly, the DHW temperature sensor may be faulty and should be tested and replaced if needed.