What is a TXV? (Thermostatic Expansion Valve)

Air Conditioning, FAQs

What is a TXV? A thermostatic expansion valve (TXV) is a device that controls the flow of refrigerant into the evaporator coil of your home HVAC system. The TXV works by sensing the temperature of the refrigerant in the evaporator coil and adjusting the flow of refrigerant accordingly. This ensures that the evaporator coil is always operating at the optimal temperature, which maximizes the efficiency of your HVAC system.

How long does a TXV last? Though it is uncommon for a TXV to malfunction, it does happen. We cannot put a time line on the part itself, but it is part of an air condition system which most of the time is covered under parts warranty for up to 10 years. Many systems wear out before a TXV goes bad. 

Whys does a TXV malfunction? The TXV can malfunction two different ways. The first way the TXV can malfunction is that the sensing bulb that controls opening and closing of the valve goes bad. The second way is the the internal parts of the TXV become clogged with micro-debris. To prevent clogs, Air & Electrical Services installs filters on every system we install or repair. The filter catches most debris that can be in the refrigerant system, but some small debris can still make its way through to cause TXV issues.

Is replacing your TXV an expensive repair? The replacement of a TXV is an expensive because of the steps necessary to install a new one. It is a time extensive process that includes removing refrigerant from the system, soldering in a new TXV, evacuating the system, and reinstalling the refrigerant.