5353 - Bosch Heat Pump Z2 asynchronous drive on compressor alarm

What does 5353 mean?

This alarm indicates that the compressor motor in Bosch Heat Pump zone 2 is not running synchronously. It triggers after 3 warnings within 3 hours, or if a warning is active for 30 minutes. The system may reset after 4 minutes if the cause is resolved.

• Gap or failure in cabling between the compressor and inverter.
• Compressor sensor TR1 providing an incorrect value.
• Electrical fault within the compressor or inverter.

Click steps to track your progress.

1. 1

   Check all visible cabling and connections between the compressor and the inverter for any gaps, damage, or loose connections.

2. 2

   If an I/O board was recently replaced, contact your installer to verify the rotary encoder adjustment.

3. 3

   Reset the Heat Pump system by cycling its power.

4. 4

   If the problem persists, contact a qualified technician to check sensors, wiring, and inverter components.