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Carrier · Air conditioner

99 High torque lockout

High severity Carrier Infinity 19VS 24VNA9

What the control is telling you

Amber STATUS light flashes 99. High torque kept happening on the lowest stage (elevated from code 98). 2-hour lockout. Type: System malfunction; reset: 2 hours.

Applies to: Carrier Infinity 19VS variable speed air conditioner 24VNA9 (AOC control + inverter)

Likely causes

  • Overcharged system
  • Compressor leads miswired at U, V, W
  • Outdoor airflow too low or off
  • Expansion device restriction (TXV)

Test and repair steps

  1. Cooling check subcooling in Charging Mode (or the subcooling chart on the control box door) and adjust charge.
  2. Check compressor lead order at U, V, W.
  3. Check the outdoor coil and fan.
  4. Troubleshoot the TXV.

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Source: Carrier 25VNA8 / 24VNA9 Service Manual, Table 6 Fault Code Actions, p.26. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.