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Carrier Error Code 25: Invalid model plug / inverter size (AC)

Updated · by Aurora Star Tech Inc.

Carrier error code 25 on a air conditioner means: Invalid model plug / inverter size. It is also called Carrier diagnostic code 25.

High severityAir ConditionerAlso Heat PumpCarrier Infinity 19VS 24VNA9 · Carrier 2-stage 24ANB/25HNB

Homeowner? What Carrier code 25 means for you

Call a technician Your air conditioner is reporting: Invalid model plug / inverter size. The air conditioner 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.
  • Keep about 2 feet around the outdoor unit clear of leaves, grass and debris.
  • If you see ice on the pipes or the indoor coil, turn the system off and run only the fan for a few hours, then call a technician.
  • 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 25 mean?

Amber STATUS light flashes 25. The AOC board cannot read a valid model plug, or the plug does not match the inverter size, so the unit will not run. Type: System malfunction; reset: None (fix and power cycle).

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

Common causes of Carrier code 25

  • Model plug missing, damaged, corroded or not fully seated
  • Wrong model plug for this unit
  • Plug size does not match the inverter size (e.g. 2-ton plug with 3-ton inverter)

A technician checks these and 1 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 25

24ANB12424ANB13624ANB14824ANB16024ANB72424ANB73624ANB74824ANB76024VNA924VNA91324VNA92424VNA92524VNA93624VNA93724VNA94824VNA94924VNA960

Other Carrier AC codes

CodeMeaning
16Lost communication with user interface
31High pressure switch open
32Low pressure trip
33Lost inverter communication
45Outdoor control board failure
46Brownout
47No 230 V at unit
48Lost inverter communication - lockout
49Compressor over current
53Outdoor air temperature sensor fault
54Suction temperature sensor fault
55Outdoor coil temperature sensor fault

All Carrier Air Conditioner error codes →

Carrier code 25: homeowner questions

What does Carrier code 25 mean?

Invalid model plug / inverter size. Amber STATUS light flashes 25. The AOC board cannot read a valid model plug, or the plug does not match the inverter size, so the unit will not run. Type: System malfunction; reset: None (fix and power cycle).

Is it safe to keep using my air conditioner with code 25?

It depends on the cause. The air conditioner 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 25 myself?

You can try one reset (power off for 30 seconds, then on). If Carrier code 25 comes back, the cause is still there and a licensed technician should check it.

Who can fix Carrier code 25 near me?

Aurora Star Tech Inc. repairs Carrier air conditioners 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

Troubleshooting guides

Source: Carrier 25VNA8 / 24VNA9 Service Manual, Table 6 Fault Code Actions, p.19. 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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