Expansion Valve (TXV) Replacement — AC Repair

Professional Expansion Valve (TXV) Replacement — AC Repair in Asheville & Western NC

What the TXV Does in Your AC System

The thermostatic expansion valve (TXV) meters the precise amount of liquid refrigerant entering the evaporator coil. It's a critical component for efficient cooling — too much refrigerant floods the coil and risks compressor damage; too little starves the coil and reduces cooling capacity. When a TXV fails, it typically sticks in one position — either flooding or starving the evaporator — causing symptoms like poor cooling, ice formation, high head pressure, or compressor overheating.

A Difficult Diagnosis Done Right

TXV problems are notoriously tricky to diagnose because the symptoms mimic other refrigerant system issues. Low superheat could be a TXV problem or an overcharge. High superheat could be a TXV problem or a low charge from a refrigerant leak. Our technicians use superheat and subcooling measurements, along with temperature differential readings and pressure analysis, to isolate the TXV as the specific failure point before recommending replacement.

Precision Replacement Work

TXV replacement involves recovering refrigerant, removing the failed valve, brazing in the new valve (matched to your system's tonnage and refrigerant type), replacing the filter-drier, evacuating the system with a vacuum pump, and recharging to manufacturer specifications. It's detailed work that requires proper tools and training — the kind of AC repair that Quality Comfort handles expertly for homeowners across Asheville and Western NC.