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5 Common Symptoms of a Bad AC Expansion Valve (& Replacement Cost)

Expansion Valve For Air Conditioner

In most households and offices, issues with air conditioning are the most common, and among the most common issues with air conditioners is a bad expansion valve.

So, what causes the AC expansion valve to go wrong? What are the options for a consumer to deal with this issue?

Key Takeaways

Most expansion valves can be repaired or replaced cheaply, but how do you know the symptoms of a bad expansion valve? And what to do when you encounter the malfunction of this basic component of your air conditioner?

If you are observing fluctuation in its ability to control refrigerant flow in the unit, if the temperature is inconsistent, too cold, or warm, just hang on here; we are going to fix the AC expansion valve or replace it based on the observation of common symptoms.

Dealing with bad AC expansion valves, there are various essential concerns like Physical Risk, Environmental Hazard and Electricity Cost.

5 Common Symptoms of a Bad AC Expansion Valve

There could be various reasons that your AC expansion valve went wrong; just focus on these common symptoms.

1. The Unit Doesn’t Go Off at the Setting

Display Panel Of A Domestic Ac Unit

The air conditioner senses the temperature inside and outside of the unit with the help of basic Internal components; the air conditioner goes off automatically when it detects the temperature of the setting; if it does not, there must be a problem with the temperature detection.

If this symptom keeps recurring, it is usually the case of a faulty or broken expansion valve. Contact any HVAC technician for help.

2. Frozen Coils in the Unit

Aluminum Fins Of Condenser For Air Conditioner

Amongst the main functions of an expansion valve is to cool the refrigerant by depressurizing it; if it fails, the refrigerant will freeze the coils by cooling it uncontrollably. This is a clear symptom that your unit’s expansion valve is not working properly.


Handling the refrigerant is too risky; you must have it checked by a trained HVAC technician.

3. Fluctuations in Refrigerant Flow

Air Conditioner Air Flow

If you observe an inconsistency in air-flow temperatures, you shouldn’t play around with the setting to control it; this might also be the symptom of a bad AC expansion valve. It happens because the air flows back and forth between the air vents.

Before making any decisions to replace the valve, have your unit inspected by an expert so that you can rule out the replacement cost by having only the controller fixed.

4. AC Blowing Warm Air

Man Feels Extremely Hot Air From Ac

Blowing warm air by an air conditioner can have more than one reason, and the bad expansion valve is one of them. This is essentially one of those symptoms for which you must have the air conditioner checked by an expert.

Blowing warm air can also be the result of leaking valves or low refrigerant levels. Once the expert rules out these two reasons, your expansion valve must be defective and might require to be replaced.

5. The Compressor Won’t Go Off

Outdoor Compressor Unit Of A Split Ac

This symptom could be the most critical one since it affects the compressor gas and electricity bill. Your air conditioner will be operating without going off but will waste the gas and exhaust the compressor because your expansion valve is not shutting down the unit properly.

Don’t waste any time, and replace the expansion valve immediately.


After observing the above symptom, any delay can cost you an accumulative amount for gas charging, expansion valve replacement, and a high electricity bill. Keep the main power supply off until the HVAC expert arrives.

There can be about 20 more symptoms that can indicate a bad AC expansion valve. We have covered the most common ones, but every solution comes with a cost.

Expansion Valve Replacement Cost

Old Expansion Valve Air Conditioner

Different air conditioner manufacturing companies can use different types of expansion valves ranging from $200 to $800.

Average Equipment Cost

The most commonly used AC expansion valves cost around $400 locally, but there is always an option to purchase cheaper valves online (not recommended).

Labor Cost

Labor Costs can vary from $150 to $300 depending on the workload and the amount of fuel adjustment involved. If it seems too high, hire a friend!

Overall Replacement Cost

To reach an accumulative average cost to replace a bad AC expansion valve ranges from $500 to $700.


Professional Technician Maintaining Modern Air Conditioner

If you have reached this long, covering the whole article, you would have a clear idea that it’s not that simple to fix an AC expansion valve, but once you are aware of the common symptoms, you will know exactly when to call the HVAC technician.


Always ensure you do not touch the components that involve the risk of harm and leave the issue to the field expert.

Frequently Asked Questions

What Makes an Expansion Valve Go Bad?

Most commonly, expansion valves go wrong because of these issues.

  • Overheating of the valve.
  • Contaminants entering into the valves or internal components.
  • Voltage issue because of inconsistent power supply.
  • Blocked inlet pipes.

Can a Bad Expansion Valve Cause Leakage?

Yes! When the valve malfunctions, the unit may suffer a refrigerant leak.

How Much Does an Expansion Valve Cost?

On average, a new AC expansion valve costs around $400.

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