Alarm 353 - Failed start, no pressure diff.

What does 353 mean?

The pressure difference between sensors BP9 and BP8 has been too low at compressor start 3 times within 30 minutes. This indicates the compressor is not effectively compressing refrigerant.

• Fault in pressure sensor BP8, BP9.
• The compressor does not compress the refrigerant sufficiently.
• Compressor breakdown.

Click steps to track your progress.

1. 1

   Turn off the Heat Pump at the main power switch for a few minutes, then turn it back on to reset the system.

2. 2

   Check the indoor module/control module for any other related alarms or diagnostic messages.

3. 3

   If the alarm persists, contact a qualified NIBE service technician for an inspection of the pressure sensors and the compressor.