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5410

Alarm Heat Pump Z1 air intake temperature sensor TL2 faulty

Bosch · Heat Pumps

What does 5410 mean?

This alarm indicates a fault with the air intake temperature sensor TL2 in Heat Pump Z1, possibly due to a failure or short circuit. It triggers after 3 faults in 2 hours, or 15 minutes of continuous failure or short circuit.

Common Causes

  • Air intake sensor TL2 or its signal cable failure.
  • Screw terminal on the I/O board to sensor TL2 not tightened.
  • Air intake sensor TL2 or its signal cable short circuited.
  • Defective I/O board.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Locate the I/O board and check the screw terminal connection for the air intake sensor TL2 to ensure it is tightened.

  2. 2

    If the alarm persists, contact a qualified technician to check the sensor and its cabling.

  3. 3

    Contact customer support if the issue continues.

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 7)Search more codes in this manual