1500 — Low discharge temperature causing superheat trouble

What does 1500 mean?

This code indicates that the compressor's discharge temperature is too low, leading to abnormally low superheat. This problem is detected when the discharge superheat remains very low for an extended period (typically below -15°C or 5°F for 5 minutes), even when the electronic expansion valve (LEV) is set to its minimum open pulse.

• Loose or disconnected wiring for the compressor thermistor (TH4) or the indoor electronic expansion valve (LEV).
• A faulty compressor thermistor (TH4) or its holder.
• A malfunctioning electronic expansion valve (LEV) or its coil.
• Damage or breakage in the LEV wiring or connector.

Click steps to track your progress.

1. 1

   Turn off the main power to the unit at the circuit breaker for safety.

2. 2

   Carefully inspect the wiring and connectors for the compressor thermistor (TH4) to ensure they are securely connected and not loose or damaged.

3. 3

   Inspect the wiring and connector for the indoor electronic expansion valve (LEV) for any signs of disconnection, half-disconnection, or breakage. Reconnect any loose parts.

4. 4

   Restore power to the unit and see if the error clears after the system attempts to restart.