Error Code: EH 65 – Evaporator Coil Temperature Sensor (T2A) Open Circuit or Short Circuit

Error Code: EH 65 – Evaporator Coil Temperature Sensor (T2A) Open Circuit or Short Circuit

What this means:
The T2A sensor, which monitors the evaporator coil temperature, is reporting a signal that is either too low (< 0.06V)or too high (> 4.94V). This indicates a short circuit or open circuit, preventing the system from accurately measuring the coil temperatureTS23.

Try this first (quick reset):

1. Turn off power to the unit completely.

2. Wait at least 2 minutes.

3. Turn it back on and observe the system.

• If the error clears — the issue may have been a temporary glitch.

• If the error returns — follow the sensor diagnostic steps below.

Next steps (for technicians):

1. Inspect wiring from T2A sensor to PCB:

   • Ensure there is no damage or loose connection.

   • Reseat or replace the wire as needed.

2. Measure the sensor resistance:

   • If resistance is not within the normal range → replace the T2A sensor.

   • If resistance is normal but the error remains → replace the indoor PCB.

What you might need:

• T2A sensor

• Indoor PCB

• Connection wires

Helpful tip:
EH 65 is part of the standard indoor sensor fault group (EH 60–66). These all follow the same diagnosis logic: check wiring, then test the sensor, and finally the PCB if needed.

Click here to view the detailed guide.TS23