To Bleed or Not to Bleed: Does It Matter Which TXV You Choose?
By Ken

When it comes to thermostatic expansion valves (TXVs), you've basically got two options: bleed and non-bleed. The "bleed" style is often just called a bleed TXV, while the "non-bleed" version might go by TXV or hard shut-off TXV (HSO)—depends on the manufacturer.

So, what’s the actual difference? It all comes down to equalization—specifically, how fast the pressures equalize between the high and low side when the system shuts off. This equalization matters because it directly affects how the compressor starts up.

Bleed vs. Non-Bleed: What Changes?

• Bleed TXVs allow pressures to equalize slowly when the system is off. That means the compressor doesn’t have to fight a huge pressure difference when it kicks on. It’s easier on the compressor and reduces the chance of locked rotor amps (LRA) on startup.

• Non-bleed (hard shut-off) TXVs, on the other hand, lock in the pressure difference. There’s no internal equalization through the valve, so the compressor might hit those locked rotor amps when starting up. In that case, a hard start kit—a capacitor and relay—can help get things moving.

So Why Use a Non-Bleed TXV at All?

Good question. Non-bleed TXVs actually have an important job: they help prevent refrigerant migration and flooded starts. When the system shuts down, a non-bleed TXV traps refrigerant in the condenser, not the evaporator. That way, the compressor isn’t starting against a slug of liquid refrigerant, which can wreck it over time.

But because of that pressure differential at startup, manufacturers sometimes recommend a hard start kit, even on scroll compressors, to keep things safe and reliable.

Bottom Line:

• Want easier startups? Go with a bleed TXV or use a hard start kit if you're sticking with a non-bleed.

• Want to reduce refrigerant migration risks? Stick with the non-bleed TXV—just be ready to support the compressor on startup.

In short: yes, it does matter which TXV you choose. Each one has its pros and cons, and the right answer depends on your system and the compressor you're working with.