Fault Code Lookup

HVAC Sales Master
53-41
Outdoor suction temperature (OST) sensor open (heat pump)
This code typically points to
  • Failed OST thermistor
  • Broken sensor wire

Next checks to confirm
  1. Measure OST resistance
  2. Verify wiring

Escalation
Replace sensor after wiring confirmed good.
Reset behavior
Clears when sensor reading returns to valid range.
Service Soon
Schedule repair
Need deeper detail?
Retrieve the subcode for this platform:
  1. From the main screen, touch Menu
  2. Touch and hold the Service icon for at least 10 seconds until it turns green
  3. Open Service Information
  4. Use View Diagnostics for the most recent fault's top three likely root causes
  5. Use Last 10 System Events for timestamped recent events
  6. Use Run/Fault History for resettable fault counters, cycle counters, and run times
Source
Carrier inverter heat pump service manual