Noritz
Flow Sensor Not Detecting Demand
No hot water; Noritz unit has power but does not start when hot water taps are opened (no error code displayed).
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Clogged inlet water filter, Failed flow sensor (turbine), Stuck flow control valve, Very low flow from fixtures below activation threshold
How to Fix / Troubleshooting
Safety first: Turn OFF power and close water isolation valves before removing filters or sensors.
Steps to check and correct:
- Clean inlet filter: Remove and rinse the cold inlet water filter screen on the Noritz unit to clear sediment.
- Check fixture flow: Remove aerators from faucets and showerheads and clean them. Test with multiple fixtures fully open.
- Listen for internal click: When opening a hot tap, you should hear internal relays or valves. If not, the flow sensor may not be signaling the PCB.
- Professional service: If cleaning filters and fixtures does not restore operation, the flow sensor or flow control valve likely needs testing and replacement by a Noritz technician.
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Repair Difficulty
Medium
3/5
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