❄️Air Conditioner

CODE-31

Carrier · Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence

Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence CODE-31 Error Fix: Infinity Code 31 — High-Pressure Protection

The Infinity System Control displays "Code 31" indicating the outdoor unit has shut down due to high refrigerant head pressure. The high-pressure switch or transducer has detected pressure above the safe operating limit. Causes (in order of likelihood): (1) Dirty condenser coil — the most common cause. Clean the outdoor coil thoroughly. (2) Condenser fan motor not running — the fan must pull air through the coil for heat rejection. Check the fan motor and capacitor. (3) Refrigerant overcharge — if a technician recently added refrigerant and added too much, head pressure increases dangerously. (4) Non-condensables (air) in the system — from an improper installation or service. (5) TXV stuck open flooding the evaporator. On Infinity/Greenspeed variable-speed units, the system modulates compressor speed to manage pressures — a Code 31 means pressures exceeded even the slow-speed limits, indicating a significant problem.

High severity2 fixes available

Quick Answer

Error CODE-31 on the Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence means: Infinity Code 31 — High-Pressure Protection. The top-ranked community fix is “Test and Replace Condenser Fan Motor and Capacitor” (hard difficulty, ~90 min, DIY cost: $0-$20). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · air conditioner

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

When to Call a Professional

While many air conditioner repairs can be done safely at home, consider hiring a qualified technician if:

This is a high severity error — continued use may cause damage or a safety hazard
The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $200-$350.

Other Carrier Models with Error CODE-31

Carrier 25VNA Infinity Greenspeed Variable-Speed Heat Pump

heat_pump · 2 fixes

Other Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence Error Codes

CODE-12

Infinity Code 12 — No Cooling / Call Not Satisfied

2 fixes

CODE-32

Infinity Code 32 — Low-Pressure Protection

2 fixes

CODE-33

Infinity Code 33 — Outdoor Coil Thermistor Open/Short

2 fixes

CODE-34

Infinity Code 34 — Indoor Coil Thermistor Issue

2 fixes

CODE-51

Infinity Code 51 — Over/Under Charge Protection

2 fixes

CODE-52

Infinity Code 52 — Outdoor Unit Lost Communication

2 fixes

CODE-53

Infinity Code 53 — Indoor Unit Lost Communication

2 fixes

CODE-61

Infinity Code 61 — Compressor Protection (Low Speed)

2 fixes

People Also Ask About Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence Error CODE-31

What does error code CODE-31 mean on a Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence?

Error code CODE-31 on the Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence means: Infinity Code 31 — High-Pressure Protection. The Infinity System Control displays "Code 31" indicating the outdoor unit has shut down due to high refrigerant head pressure. The high-pressure switch or transducer has detected pressure above the safe operating limit. Causes (in order of likelihood): (1) Dirty condenser coil — the most common cause. Clean the outdoor coil thoroughly. (2) Condenser fan motor not running — the fan must pull air through the coil for heat rejection. Check the fan motor and capacitor. (3) Refrigerant overcharge — if a technician recently added refrigerant and added too much, head pressure increases dangerously. (4) Non-condensables (air) in the system — from an improper installation or service. (5) TXV stuck open flooding the evaporator. On Infinity/Greenspeed variable-speed units, the system modulates compressor speed to manage pressures — a Code 31 means pressures exceeded even the slow-speed limits, indicating a significant problem.

How do I fix error code CODE-31 on my Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence?

The most successful fix is "Test and Replace Condenser Fan Motor and Capacitor" (hard difficulty, ~90 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

Is error code CODE-31 on a Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence serious?

This error is rated high severity. You should address it promptly — continued use could cause damage or safety concerns.

Can I fix Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence error CODE-31 myself?

Yes — the top-ranked community fix ("Test and Replace Condenser Fan Motor and Capacitor") is rated hard difficulty and takes about 90 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Nut driver set, Needle nose pliers.

How much does it cost to repair Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence error CODE-31?

DIY cost: $0-$20. Professional repair typically costs $200-$350. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence have?

The Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence has 8 other known error codes, including: CODE-12 (Infinity Code 12 — No Cooling / Call Not Satisfied), CODE-32 (Infinity Code 32 — Low-Pressure Protection), CODE-33 (Infinity Code 33 — Outdoor Coil Thermistor Open/Short), CODE-34 (Infinity Code 34 — Indoor Coil Thermistor Issue), CODE-51 (Infinity Code 51 — Over/Under Charge Protection), and 3 more.

Which other Carrier models have the CODE-31 error?

Error code CODE-31 also appears on 1 other Carrier model: Carrier 25VNA Infinity Greenspeed Variable-Speed Heat Pump. The fix may vary by model, so check each model's specific page for tailored repair steps.

What other error codes does the Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence have?

The Carrier Carrier 26VNA1 Infinity 21 Variable-Speed Air Conditioner with Greenspeed Intelligence has 8 other known error codes:

Which other Carrier models have the CODE-31 error?

Error code CODE-31 also appears on 1 other Carrier model:

Carrier 25VNA Infinity Greenspeed Variable-Speed Heat Pump (heat pump) · 2 fixes

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