System Components
Expansion Valve (TXV)
A precision device that controls the flow of liquid refrigerant into the evaporator coil, regulating how much refrigerant enters based on cooling demand.
What Is a Expansion Valve (TXV)?
The thermostatic expansion valve (TXV) is a critical component that meters liquid refrigerant into the evaporator coil at exactly the right rate. It uses a temperature-sensing bulb to monitor the refrigerant leaving the coil and adjusts its opening to maintain proper superheat — ensuring the coil is used efficiently without liquid refrigerant reaching the compressor (which would cause damage). A malfunctioning TXV can cause poor cooling, ice buildup, or compressor damage.
Why It Matters for Your Home
TXV problems are often misdiagnosed as low refrigerant or other issues by less experienced technicians. A stuck or improperly adjusted expansion valve can mimic the symptoms of a refrigerant leak, leading to unnecessary and expensive refrigerant charges. Proper diagnosis requires measuring superheat and subcooling — this is where experienced troubleshooting expertise really matters.
Getting conflicting diagnoses on your AC? Call Trademark Tek at 541-500-0663 for expert troubleshooting.
Quick Facts
Category
System Components
Also Known As
Expansion Valve (TXV)
