Alarm 156 — Low LP cool (Low Pressure in Cooling)

What does Alarm 156 mean?

The system reports a continuous low pressure alarm during cooling operation with the F2040 unit. This typically indicates a problem with the cooling circuit's pressure or an issue with the system's regulation.

• Incorrect regulation in cooling mode with the F2040 outdoor unit.
• Low refrigerant levels in the cooling circuit.
• Potential issue with the pressure sensor (LP sensor) itself.

Click steps to track your progress.

1. 1

   Check the F2040 unit and its surroundings for any physical obstructions or issues.

2. 2

   Ensure proper airflow around the outdoor unit to prevent heat buildup.

3. 3

   Update the NIBE SMO 20 firmware to version 8700R4 or later.

4. 4

   If the alarm persists, contact qualified service personnel to check refrigerant levels and pressure sensors.