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5528

5528 - Bosch Heat Pump Z2 compressor sensor TR1 failure warning

Bosch · Heat Pumps

What does 5528 mean?

This warning indicates a failure of compressor sensor TR1 in Bosch Heat Pump zone 2. It triggers after 3 faults (reading >364 kOhm) in 2 hours.

Common Causes

  • Compressor sensor TR1 has failed.
  • The I/O board is not working correctly.
  • Damage or poor connection in the sensor's wiring.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Power cycle the Heat Pump to reset the system and see if the warning clears.

  2. 2

    Check for any visible damage to the wiring connected to compressor sensor TR1.

  3. 3

    If the warning persists, contact a qualified technician to test sensor TR1 and the I/O board for proper function.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

5203Alarm Outdoor sensor TL1 faulty5206Alarm Flow sensor T0 faulty5209Alarm Z1 heat transfer fluid out sensor TC1 faulty
Source: Bosch Heat Pumps
Open Manual (Page 11)Search more codes in this manual