Fieldpiece Lightzone Liike 08781 normaal 2

The Electronic Expansion Valve (EEV): What It Does, Common Issues, and Troubleshooting Tips

Tips for Technicians: EEV Failure

Ever been stuck on a tough repair or spent way too long figuring out a system issue? We’ve all been there. This new blog series is packed with practical advice, smart solutions, and hands-on tips you can immediately use to solve problems faster and work smarter. No fluff—just the information that makes a difference when you're out in the field.

What Does an EEV Do?

The EEV uses electronic signals to control the flow of refrigerant into the evaporator coil. It receives input from system sensors—such as temperature and pressure—and adjusts refrigerant flow in real time.

This level of control helps:

Maintain precise superheat
Improve cooling performance
Protect system components
Maximize energy efficiency under varying loads

EEVs are commonly used in refrigeration systems.

Common signs of EEV failure

When an electronic expansion valve (EEV) is not operating correctly, it can lead to system inefficiencies, cooling issues, or even equipment damage. These are the most common signs to watch for in the field:

1. High superheat

This typically indicates that the valve is not allowing enough refrigerant into the evaporator.

2. Low superheat or flooding

This can occur when the EEV is stuck open or overflowing refrigerant into the evaporator.

3. Fluctuating pressures or inconsistent cooling

Erratic valve movement or control issues can cause unstable system operation.

How To Troubleshoot an EEV

To troubleshoot a faulty electronic expansion valve (EEV), start by checking that it’s receiving power from the control board. Look for any loose, damaged, or corroded wiring connections. Next, listen for the sound of the valve operating—during startup or changes in system mode, a working EEV usually makes a soft clicking or buzzing noise. If there's no sound, the valve motor or control signal could be the issue. Measure the system’s superheat to see if it matches expected values; if superheat is too high or too low, the EEV may not be metering refrigerant correctly. Also check for any blockages inside the valve—dirt, oil, or debris can restrict flow and affect performance. If available, use the system’s diagnostic mode to manually open or close the valve. This can help you determine whether the problem is mechanical or electronic.

In Short

A properly functioning EEV ensures your HVACR system delivers the right amount of refrigerant at the right time. By recognizing the symptoms of EEV failure and using a structured troubleshooting process, you can restore performance quickly and avoid costly repairs.

Need reliable tools to support your diagnostics?

Explore the full range of Fieldpiece tools for HVACR professionals.

Interested in more information?

Leave your contact details with us and receive updates, tips, information, videos, and much more!

First name

Last name

E-mail address

For more information about our privacy practices please visit our privacy police on this website. By clicking below, you agree that we may process your information in accordance with these terms.