State tankless water heater shows E06; water temperature fluctuates or unit shuts down.

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

Open or shorted outlet thermistor, Loose thermistor mounting, Damaged harness to control board

Safety: Turn off power before servicing.

Locate outlet thermistor: Remove the front cover and find the sensor attached to the hot outlet pipe or heat exchanger outlet.
Check mounting: Ensure the sensor is firmly clamped to the pipe or seated in its well with good thermal contact. Re-secure if loose.
Inspect wiring: Look for pinched or burned wires. Reseat the connector at the control board.
Test and replace: Measure resistance and compare to spec. Replace the outlet thermistor if out of range.

Medium 3/5

Outlet Temperature Sensor (Thermistor)

Check Price on Amazon

We may earn a commission from links on this page.