State tankless water heater shows E16; unit may overheat at low flow conditions.

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.

Possible Causes

Partially blocked heat exchanger, Incorrect minimum flow setting, Faulty flow sensor calibration

Safety: Turn off power and gas before maintenance.

Clean inlet filter: Remove and clean the cold inlet filter screen to ensure proper flow.
Descale: Perform a descaling flush of the heat exchanger to restore full water passage.
Check flow sensor: Inspect and clean the flow sensor turbine. Replace if worn or not reading correctly.
Verify settings: Using the State service menu (if available), confirm minimum flow and temperature rise settings are within specification.

Medium 3/5

Flow Sensor Assembly

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