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53

Fault 53 — Outdoor Air Temp Sensor Fault

Carrier · Heat Pumps

What does 53 mean?

The Outdoor Air Temperature (OAT) sensor is reporting a fault. This can be due to a disconnected, broken, or damaged sensor or wiring.

Common Causes

  • Sensor harness not connected to ODU control
  • Broken or loose harness wire
  • Broken or damaged sensor
  • Hardware damage to ODU control

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Ensure the OAT sensor plug is securely connected to the ODU control.

  2. 2

    Inspect the sensor harness wire for any breaks or loose connections.

  3. 3

    If the problem persists, contact a qualified technician to check sensor continuity and potentially replace the sensor or ODU control.

Browse all codes in this manual (40)
Verified technical data. Last updated: April 2026

Related Faults

1 (1 sec ON), longer pause (2 sec OFF)Amber LED flashes 1 time (1 sec ON) then longer pause (2 sec OFF) — Variable Capacity Range Cutback1, pauseAmber LED flashes 1 time then pauses — Variable Capacity Operation16Communication Loss Event 16
Source: Carrier Heat Pumps
Open Manual (Page 15)Search more codes in this manual