❄️Air Conditioner

TXV FAILURE

Lennox · ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner

Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner TXV FAILURE Error Fix: TXV / Metering Device Failure

Thermostatic expansion valve or metering device has failed. TXV stuck closed: low suction pressure, frozen coil. TXV stuck open: high suction pressure, sweating suction line (liquid floodback risk). Diagnosis requires measuring superheat and subcooling — professional repair. XC21/XC25 use electronic expansion valves for precise metering.

High severity2 fixes available✨ Free fix available

Quick Answer

Error TXV FAILURE on the Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner means: TXV / Metering Device Failure. The top-ranked community fix is “Test and Replace Faulty TXV or Metering Device” (hard difficulty, ~120 min, DIY cost: $0-$50). 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: $400-$700.

Other Lennox Models with Error TXV FAILURE

XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner

air_conditioner · 2 fixes

XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner

air_conditioner · 2 fixes

XP21 Dave Lennox Signature Collection 20 SEER Heat Pump

heat_pump · 2 fixes

XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump

heat_pump · 2 fixes

Other Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner Error Codes

1 FLASH YELLOW

High Pressure Switch Open

2 fixes

2 FLASHES YELLOW

Low Pressure Switch Open

2 fixes

3 FLASHES YELLOW

Compressor Thermal Overload

2 fixes

4 FLASHES YELLOW

Short-Cycle Protection

2 fixes

CAPACITOR FAILURE

Capacitor Failure (Run/Start)

Compressor Failure

Condenser Fan Motor Failure

2 fixes

CONTACTOR FAILURE

Contactor Failure

2 fixes

People Also Ask About Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner Error TXV FAILURE

What does error code TXV FAILURE mean on a Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner?

Error code TXV FAILURE on the Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner means: TXV / Metering Device Failure. Thermostatic expansion valve or metering device has failed. TXV stuck closed: low suction pressure, frozen coil. TXV stuck open: high suction pressure, sweating suction line (liquid floodback risk). Diagnosis requires measuring superheat and subcooling — professional repair. XC21/XC25 use electronic expansion valves for precise metering.

How do I fix error code TXV FAILURE on my Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner?

The most successful fix is "Test and Replace Faulty TXV or Metering Device" (hard difficulty, ~120 minutes). Estimated DIY cost: $0-$50. HomeMD has 2 community-ranked fixes for this error.

Is error code TXV FAILURE on a Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner serious?

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

Can I fix Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner error TXV FAILURE myself?

Yes — the top-ranked community fix ("Test and Replace Faulty TXV or Metering Device") is rated hard difficulty and takes about 120 minutes. Tools needed: T20 Torx screwdriver, Refrigerant gauges, Vacuum pump, Thermometers, Multimeter.

How much does it cost to repair Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner error TXV FAILURE?

DIY cost: $0-$50. Professional repair typically costs $400-$700. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner have?

The Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner has 8 other known error codes, including: 1 FLASH YELLOW (High Pressure Switch Open), 2 FLASHES YELLOW (Low Pressure Switch Open), 3 FLASHES YELLOW (Compressor Thermal Overload), 4 FLASHES YELLOW (Short-Cycle Protection), CAPACITOR FAILURE (Capacitor Failure (Run/Start)), and 3 more.

Which other Lennox models have the TXV FAILURE error?

Error code TXV FAILURE also appears on 4 other Lennox models: XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner, XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner, XP21 Dave Lennox Signature Collection 20 SEER Heat Pump, XP25 Dave Lennox Signature Collection Variable-Capacity 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 Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner have?

The Lennox ML14XC1 Merit Series 14 SEER Single-Stage Air Conditioner has 8 other known error codes:

1 FLASH YELLOW — High Pressure Switch Open (2 fixes)
2 FLASHES YELLOW — Low Pressure Switch Open (2 fixes)
3 FLASHES YELLOW — Compressor Thermal Overload (2 fixes)
4 FLASHES YELLOW — Short-Cycle Protection (2 fixes)
CAPACITOR FAILURE — Capacitor Failure (Run/Start) (2 fixes)
COMPRESSOR FAILURE — Compressor Failure (2 fixes)
CONDENSER FAN FAIL — Condenser Fan Motor Failure (2 fixes)
CONTACTOR FAILURE — Contactor Failure (2 fixes)

Which other Lennox models have the TXV FAILURE error?

Error code TXV FAILURE also appears on 4 other Lennox models:

XC21 Dave Lennox Signature Collection 21 SEER Variable-Capacity Air Conditioner (air conditioner) · 2 fixes
XC25 Dave Lennox Signature Collection 26 SEER Variable-Capacity Air Conditioner (air conditioner) · 2 fixes
XP21 Dave Lennox Signature Collection 20 SEER Heat Pump (heat pump) · 2 fixes
XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump (heat pump) · 2 fixes

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