When your air conditioner stops cooling like it used to, one part we often check first is the expansion valve. At Rocket City Air here in Huntsville, we get plenty of calls from homeowners noticing weak airflow or rising indoor temps. And sometimes, it’s not the thermostat or the refrigerant—it’s that small but mighty valve that helps control how refrigerant flows through your system.
Let’s walk through some of the most common warning signs we see when an expansion valve starts to fail, and what you can do about it.
What Is the Expansion Valve and Why Does It Matter?
Before we get into the symptoms, it helps to understand what this component does. The expansion valve regulates the flow of refrigerant into your evaporator coil. It adjusts pressure and temperature levels so your AC can remove heat from your home efficiently. If this valve isn’t working right, your system will struggle to cool air properly—especially during hot Huntsville summers.
Expansion Valve Failure Can Cause Inconsistent Cooling
One of the first signs of trouble is uneven temperatures in your home. Maybe one room feels fine, but another is warm and stuffy. This could mean your expansion valve is stuck open or closed, preventing the right amount of refrigerant from reaching certain areas of the system.
Ice Buildup on the Coils May Signal Trouble
If you see frost or ice forming on your indoor coil or refrigerant lines, don’t ignore it. While this might seem harmless, it’s often a sign that the expansion valve isn’t metering refrigerant correctly. Too much or too little refrigerant flow causes temperatures to drop too low, and moisture in the air freezes.
What to Do If You See Ice
Turn the system off and call a professional. At Rocket City Air, we’ve helped dozens of homeowners across Madison County solve this issue quickly before it caused more damage.
Expansion Valve Problems Can Raise Energy Bills
If your power bill has jumped and your AC habits haven’t changed, your system could be working harder than it needs to. A malfunctioning expansion valve can throw the entire system off balance. Since it controls refrigerant pressure, your compressor may overwork to compensate for poor cooling.
Don’t Ignore Sudden Spikes
Energy waste doesn’t just cost you money. It shortens the life of your equipment. We’ve seen it time and time again across Huntsville neighborhoods—small issues like this can lead to big repairs when left unchecked.
Strange Noises Could Mean Problems
Another symptom to watch for is hissing, gurgling, or knocking sounds coming from your AC unit. While these can point to several issues, they often signal refrigerant flow problems. If the expansion valve is stuck or clogged, the sound of refrigerant struggling to move through the system becomes noticeable.
Weak Air Flow and Poor AC Performance
Finally, weak airflow from your vents can also suggest expansion valve trouble. If the valve is too restricted, your evaporator coil may not get cold enough. That leads to warm air coming out of your vents instead of the refreshing blast you expect.
When to Call Rocket City Air
If you’ve noticed any of these issues, it’s best to have a technician take a look. Diagnosing a faulty expansion valve isn’t something you can do on your own without the right tools and experience. At Rocket City Air, we handle AC repairs like this every day—from downtown Huntsville to every corner of Madison County. We’ll inspect the valve, run pressure checks, and get your AC back in shape fast.
Don’t Let an Expansion Valve Disrupt Your Comfort
While small, the expansion valve plays a huge role in your air conditioning system. If it’s not working right, your home won’t stay cool, your system will work harder, and you might end up with major repair costs. If you’re in Huntsville or the surrounding areas, give Rocket City Air a call. We’ll check everything out and give you honest answers about what’s going on.
