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CODE-45

Carrier · Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower

Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower CODE-45 Error Fix: Infinity Code 45 — Control Circuit Lockout

The Infinity System Control displays "Code 45" indicating the furnace control board has entered a hard lockout state due to repeated safety faults. This is similar to LED 1-blink but specific to the Infinity communication system. The control board tracks recurring faults and if the same safety condition triggers too many times in a given period, it locks out and requires manual intervention to reset. The Infinity Control fault log stores the history of what led to the lockout. To reset: cycle the furnace power (turn off the power switch or breaker for 30 seconds, then restore). Before resetting, check the fault history on the Infinity Control to understand what underlying issue caused the repeated trips. Common underlying causes: dirty flame sensor (most frequent), failing pressure switch, intermittent inducer motor, or gas supply issues.

High severity2 fixes available✨ Free fix available

Quick Answer

Error CODE-45 on the Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower means: Infinity Code 45 — Control Circuit Lockout. The top-ranked community fix is “Test and Replace Pressure Switch or Inducer Motor Assembly” (hard difficulty, ~60 min, DIY cost: $10-$20). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · furnace

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 furnace 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: $250-$400.

Other Carrier Models with Error CODE-45

Carrier 59MN7 Infinity 98 Modulating 98.5% AFUE Gas Furnace with Greenspeed Intelligence

furnace · 2 fixes

Other Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower Error Codes

CODE-21

Infinity Code 21 — Gas Heating Lockout

2 fixes

CODE-22

Infinity Code 22 — Abnormal Flame-Proving Signal

2 fixes

CODE-23

Infinity Code 23 — Pressure Switch Fault

2 fixes

CODE-24

Infinity Code 24 — Secondary Voltage Fuse Blown

2 fixes

CODE-26

Infinity Code 26 — Line Voltage Limit Circuit Open

2 fixes

CODE-41

Infinity Code 41 — Blower Motor Fault

2 fixes

CODE-42

Infinity Code 42 — Inducer Motor Fault

2 fixes

CODE-43

Infinity Code 43 — Low Flame Signal / Dirty Flame Sensor

2 fixes

People Also Ask About Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower Error CODE-45

What does error code CODE-45 mean on a Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower?

Error code CODE-45 on the Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower means: Infinity Code 45 — Control Circuit Lockout. The Infinity System Control displays "Code 45" indicating the furnace control board has entered a hard lockout state due to repeated safety faults. This is similar to LED 1-blink but specific to the Infinity communication system. The control board tracks recurring faults and if the same safety condition triggers too many times in a given period, it locks out and requires manual intervention to reset. The Infinity Control fault log stores the history of what led to the lockout. To reset: cycle the furnace power (turn off the power switch or breaker for 30 seconds, then restore). Before resetting, check the fault history on the Infinity Control to understand what underlying issue caused the repeated trips. Common underlying causes: dirty flame sensor (most frequent), failing pressure switch, intermittent inducer motor, or gas supply issues.

How do I fix error code CODE-45 on my Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower?

The most successful fix is "Test and Replace Pressure Switch or Inducer Motor Assembly" (hard difficulty, ~60 minutes). Estimated DIY cost: $10-$20. HomeMD has 2 community-ranked fixes for this error.

Is error code CODE-45 on a Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower 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 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower error CODE-45 myself?

Yes — the top-ranked community fix ("Test and Replace Pressure Switch or Inducer Motor Assembly") is rated hard difficulty and takes about 60 minutes. Tools needed: Multimeter, Nut driver set, Screwdrivers (Phillips and flathead).

How much does it cost to repair Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower error CODE-45?

DIY cost: $10-$20. Professional repair typically costs $250-$400. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower have?

The Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower has 8 other known error codes, including: CODE-21 (Infinity Code 21 — Gas Heating Lockout), CODE-22 (Infinity Code 22 — Abnormal Flame-Proving Signal), CODE-23 (Infinity Code 23 — Pressure Switch Fault), CODE-24 (Infinity Code 24 — Secondary Voltage Fuse Blown), CODE-26 (Infinity Code 26 — Line Voltage Limit Circuit Open), and 3 more.

Which other Carrier models have the CODE-45 error?

Error code CODE-45 also appears on 1 other Carrier model: Carrier 59MN7 Infinity 98 Modulating 98.5% AFUE Gas Furnace with Greenspeed Intelligence. 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 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower have?

The Carrier Carrier 59TN6 Infinity 96 Two-Stage 96% AFUE Gas Furnace with Variable-Speed Blower has 8 other known error codes:

CODE-21 — Infinity Code 21 — Gas Heating Lockout (2 fixes)
CODE-22 — Infinity Code 22 — Abnormal Flame-Proving Signal (2 fixes)
CODE-23 — Infinity Code 23 — Pressure Switch Fault (2 fixes)
CODE-24 — Infinity Code 24 — Secondary Voltage Fuse Blown (2 fixes)
CODE-26 — Infinity Code 26 — Line Voltage Limit Circuit Open (2 fixes)
CODE-41 — Infinity Code 41 — Blower Motor Fault (2 fixes)
CODE-42 — Infinity Code 42 — Inducer Motor Fault (2 fixes)
CODE-43 — Infinity Code 43 — Low Flame Signal / Dirty Flame Sensor (2 fixes)

Which other Carrier models have the CODE-45 error?

Error code CODE-45 also appears on 1 other Carrier model:

Carrier 59MN7 Infinity 98 Modulating 98.5% AFUE Gas Furnace with Greenspeed Intelligence (furnace) · 2 fixes

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