Abnormal Low Pressure

What does UL mean?

The system has detected abnormally low refrigerant pressure. This typically indicates a refrigerant leak or insufficient charge, which can lead to poor cooling/heating performance and potential compressor damage.

1. 1

   Measure system low-side pressure using manifold gauges.

2. 2

   Perform a thorough leak detection test on the entire refrigerant circuit, starting from accessible joints and connections.

3. 3

   Verify refrigerant charge level — if low, recover, evacuate, and recharge to the nameplate capacity.