Heat pump heater shows E03; unit may run but not heat effectively.

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

Failed evaporator NTC sensor, Sensor dislodged from coil, Damaged sensor wiring, Control board sensor circuit fault

Safety first: Disconnect power before accessing internal components.

Locate evaporator sensor: It is usually clipped to the outdoor coil. Ensure it is firmly attached and making good contact with the coil surface.
Inspect cable: Check for cuts or damage along the sensor lead and ensure the connector is fully seated on the control board.
Reset unit: After reseating the sensor, restore power and see if E03 clears.

If the error persists, replace the evaporator sensor. If that fails, the control board may be defective.

Medium 3/5

AstralPool Evaporator Temperature Sensor

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