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Carrier Error Code 83: Low pressure lockout (4 hours) (Heat Pump)

Updated · by Aurora Star Tech Inc.

Carrier error code 83 on a heat pump means: Low pressure lockout (4 hours). It is also called Carrier diagnostic code 83.

High severityHeat PumpCarrier Infinity 18VS 25VNA8 · Carrier 2-stage 24ANB/25HNB · Carrier single-stage communicating HP

Homeowner? What Carrier code 83 means for you

Call a technician Your heat pump is reporting: Low pressure lockout (4 hours). The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
  • Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
  • In winter, keep snow and ice off and away from the outdoor unit. A short defrost cycle with steam is normal.
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Carrier error code 83 mean?

Amber STATUS light flashes 83. Suction pressure dropped below the no-operation level 3 times (elevated from code 32). 4-hour lockout. Type: System malfunction; reset: 4 hours.

Applies to: Carrier Infinity 18VS variable speed heat pump 25VNA8 (AOC control + inverter)

Common causes of Carrier code 83

  • Service valve left closed
  • Cooling: Undercharged system
  • Cooling: Indoor airflow too low or off / iced coil

A technician checks these and 6 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Carrier models that use code 83

25HNB62425HNB63625HNB64825HNB66025HNB92425HNB93625HNB94825HNB96025VNA81325VNA82425VNA82525VNA83625VNA83725VNA84825VNA860

Other Carrier Heat Pump codes

CodeMeaning
75Maximum power mode - temperature
76Fan inverter lockout
77Maximum power mode - compressor current
79Compressor / inverter fault (failed start)
81Low stage thermal lockout
82Suction over temperature lockout
84High pressure lockout (4 hours)
86Fan inverter current lockout
88Compressor / inverter lockout
91Inverter DC over voltage (event)
92Inverter DC under voltage (event)
95Compressor over current lockout

All Carrier Heat Pump error codes →

Carrier code 83: homeowner questions

What does Carrier code 83 mean?

Low pressure lockout (4 hours). Amber STATUS light flashes 83. Suction pressure dropped below the no-operation level 3 times (elevated from code 32). 4-hour lockout. Type: System malfunction; reset: 4 hours.

Is it safe to keep using my heat pump with code 83?

It depends on the cause. The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset Carrier code 83 myself?

You can try one reset (power off for 30 seconds, then on). If Carrier code 83 comes back, the cause is still there and a licensed technician should check it.

Who can fix Carrier code 83 near me?

Aurora Star Tech Inc. repairs Carrier heat pumps in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

Troubleshooting guides

Source: Carrier 25VNA8 / 24VNA9 Service Manual, Table 6 Fault Code Actions, p.23. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency HVAC Service

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