List Of Bad Expansion Valve Symptoms & Solutions

Each component of an air conditioner is essential and has a certain purpose, even a small one like the expansion valve.

During the summertime, a well-maintained air conditioning system will come in handy.

However, this crucial component occasionally fails, and understanding the reasons why this occurs is critical for quickly getting your equipment back into operation.

So, how do you know if it’s glitched? What are the signs of bad expansion valve symptoms? Let us look at some of these symptoms and how to cope with them.

How Do An Air Conditioner Expansion Valve Work?

bad expansion valve symptoms

The primary purpose of the AC expansion valve is to release pressure from the device’s liquid refrigerant.

This permits the refrigerant to expand and convert from liquid to vapor within the evaporator inlet. Furthermore, the valve regulates the refrigerant flow, referred to as the dosing unit.

A moveable rod slides upward and downward inside the expansion valves. This enables it to open and shut the inside channel, allowing or preventing the refrigerant flow.

Moreover, the rod can precisely determine the quantity of refrigerant necessary at any given moment.

Because on some hotter days, this control is required to regulate the AC expansion valve to help you feel more comfortable riding your automobile.

For example, a worn-out or faulty expansion valve over time is one of the most common contributors to expansion valve failure symptoms.

What Are The Common Symptoms Of Bad Expansion Valve Symptoms?

How do you know if your expansion valve is bad

How do you know if your expansion valve is bad? The following list will help you out in finding why your air conditioning operates in an improper working condition.

AC Continuously Running

Internal components in your air conditioner can detect the temperature inside and outside the device.

Depending on your settings, the air conditioning unit will shut off instantly after sensing a particular temperature.

If it does not switch off after installation, it is possible that there is an issue with its temperature sensor.

This is one of the symptoms of a bad expansion valve. Should the problem persist, get assistance from an HVAC specialist.

Frozen Coils In The Unit

Frozen coils are another sign of a bad expansion valve. The throttle valve’s primary function is to lower refrigerant to cool it.

If this procedure is halted or cannot be completed properly, the refrigerant will ice the coils because the temperature is too low.

Frozen coils are a sure indicator that your valve isn’t operating nicely. You should not resolve refrigerant level issues on your own.

Handling refrigerants is hazardous, and it would be better to be performed by professional HVAC experts.

AC Compressor Fails To Turn Off

When the throttle is not correctly closed, the refrigerant goes into the compressor, which continues to operate constantly while it handles the gas.

You will always know when the signs of a bad ac expansion valve occur since your AC component will keep running without stopping.

Consequently, the AC compressor may wear out quicker and require replacement or repair sooner than normal.

The heat inside your car will also be too low for comfort, and an expansion valve or compressor failure will increase energy expenses.

So, in the long run, fixing the throttle is a better solution. This is why, if this problem happens, you should book an air conditioner repair service as quickly as possible.

Strange Noises

How to know if expansion valve is bad? Check for any unexpected sounds from your equipment to see whether your throttle is defective.

A broken throttle can make your air conditioning unit emit a jingling, creaking, or knocking noise that will gradually worsen.

Therefore, once your AC compressor begins to make weird sounds while it is still running, seek assistance as soon as you can.

Fixing an expansion valve is usually inexpensive if you act quickly enough.

Poor Performance

Your air conditioner will likely experience poor performance during the hot summer because the expansion valve has malfunctioned.

When the valve breaks or has a problem, the entire valve operation of your air conditioning unit will be affected.

Depending on how serious the symptoms of a bad AC expansion valve are, the device may not react to the appropriate temperature setting or may potentially begin blowing hot air instead.

If your AC unit is underperforming, it may be due to a blocked or broken throttle.

Warm Air

A problematic throttle valve is one of the explanations why the AC delivers warm rather than cold air.

Or sometimes, the AC will blow cold then warm air. Various issues, such as low refrigerant levels or valve leaks, frequently cause it.

First, note whether your AC working fluid is lower than normal, then turn to a specialist to address the problem.

Low refrigerant levels are frequently corrected by adding extra freon to the air conditioner, which you shouldn’t do yourself.

What Are The Causes Of A Damaged A/C Expansion Valve?

AC expansion valve failure symptoms

You have explored all the AC expansion valve failure symptoms, but where do they stem from? Let’s take a look right now:

Expansion Device Blocked

The key component of the AC equipment is the throttle valve.

It not only regulates the expansion and contraction of the refrigerant, but it also serves as a filter to keep debris out of your vehicle’s AC system.

If dust or other foreign materials get caught inside this expander, they will lead to a clog and reduce the ability of the expansion valve.

To avoid this, you must keep the valve clean and clear of any blockages. You should use compressed air to clean the evaporator from any dust or debris accumulated inside the gadget.

Refrigerant Flow

Too much refrigerant flow in your car’s cooling system might entail throttle troubles. This is due to the expander’s limited capacity and inability to manage excessive coolant.

If you discover your valve is leaking, it might be because you overfilled it or did not put enough coolant into it.

To minimize this, visit a technician and correctly supply your valve with the appropriate coolant.

Note that you should never needlessly open or close the expansion unit’s valves since this might pose a threat and impair the unit’s function.

Compressor Malfunction

A compressor fault, like it turning off after a few seconds, could trigger the expansion valve to fail.

If the compressor starts to malfunction, it will not be able to transmit sufficient coolant to the expansion component, resulting in pressure issues and valve leaks.

If you are encountering these symptoms, it is probable that you need a new compressor and, therefore, should seek expert assistance.

Working Conditions

Expansion valves could go wrong because of poor working conditions.

This might include driving in excessively hot or cold weather, over puddles, or even installing an aftermarket valve incompatible with your car’s AC system.

Always use the right product and model of your car and maintain it correctly.

You should also avoid driving through puddles or using your valve after it has been idle for an extended period since this might seriously harm the valve’s internal parts and wreak havoc on the expansion valve.


How Much Does Expansion Valve Replacement Cost?

The cost of replacing a throttle depends on your car’s brand, model, and year. It can cost as low as $200 in certain circumstances and as much as $500 or more in others.

The simplest way to determine the cost of a throttle for a certain vehicle is to search online for valve replacement prices for that specific make and model.

How Can I Tell If The Expansion Valve On The AC Is Jammed Open?

While the air conditioner begins to run continually, even when the car is not operating, it is a classic sign of a blocked expansion valve.

This typically means that something obstructs the refrigerant flow, forcing the valve to stay open.


To conclude, you can easily spot the problems in your car by looking at the bad expansion valve symptoms we have shown above.

The reason behind may vary, so it’s best to have a qualified mechanic check it.

Thank you for your time reading the post. See you around!

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