4 Symptoms of a Bad A/C Expansion Valve
A properly functioning A/C expansion valve is crucial for cold air, but this valve can fail without warning. Overlooking expansion valve problems allows refrigerant leaks, pressure issues, and corrosion to sneak in, escalating costs. Learn how to recognize symptoms of a bad A/C expansion valve early on to save you time and money down the road.
How an A/C Expansion Valve Works
The main function of an air conditioner expansion valve is to remove pressure from the liquid refrigerant in the system. This allows for expansion, and then converts the refrigerant from liquid to vapor inside the evaporator. In addition, the valve controls the refrigerant flow, called metering.
Inside of the valve is a moveable rod that moves up and down. This enables it to open and close the passageway inside, allowing refrigerant to enter, or not. At any given time it can accurately meter the precise amount of refrigerant that’s needed.
Bad A/C Expansion Valve Symptoms
Generally, the first time you get a clue that something is wrong with your air conditioning it’s through a symptom of a faulty A/C expansion valve.
1) Poor Air Conditioning Performance
That first symptom is often with your A/C blowing warm air, instead of cool, even after giving the car a few minute to run on a hot day. This signifies that not enough refrigerant is getting to the evaporator.
2) Inconsistent Airflow From Vents
Simply put, the air coming out of your vents will be either too warm or too cold than what you are used to and in many cases will alternate back and forth between the two.
3) Air Conditioning Constantly Running
Another indicator is when your A/C compressor is constantly running. This is because the expansion valve will get stuck and fail to open. This means that the compressor will continue to pump refrigerant into the A/C’s system, even when you already feel cold. At this point, it’s recommended to take your vehicle to a vehicle air conditioning place to have it repaired.
4) Frost Forming on A/C Compressor or Vents
This is the opposite of #1 above. In this case, TOO MUCH refrigerant is being allowed to flow to the evaporator unmetered which eventually causes the evaporator to freeze over. In extreme cases, you may even start to notice a bit of frost forming on one or more of the interior vents in the front of the cabin or your windshield.
