How Do You Test an Expansion Valve?

It is very difficult to determine if a Thermostat Expansion Valve is clean. … Remember that an AC system MUST be clean for the compressor and other components to function properly. Any debris or contamination at the TXV can prevent proper flow of lubricating oil through the system and its return to the compressor.

How long does an expansion valve last?

There isn’t a specific lifespan of the valve, it’s more just a wear and tear kind of situation. Obviously the more you use the air conditioning, the quicker it will wear down.

Does the expansion valve need to be replaced?

I strongly recommend you change the expansion valve. … If the clutch failed there is no reason to replace the expansion valve. If it was the bearing, then you may or may not need to replace the expansion valve, depending on whether or not metal shavings were introduced into the refrigerant system.

How much does it cost to replace expansion valve?

The average cost for an air conditioning expansion valve replacement is between $346 and $470. Labor costs are estimated between $277 and $350 while parts are priced between $69 and $120. Estimate does not include taxes and fees.

What causes expansion valve to freeze?

Another reason for frozen lines in an AC unit is due to a faulty thermal expansion valve, also known as a TXV. This controls the flow of refrigerant through your AC unit. If this malfunctions then not enough refrigerant will pass through the system and the coils. That will cause a freeze up.

What is the difference between an expansion valve and an orifice tube?

Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback.

What is the purpose of an expansion valve?

Expansion Valve. The expansion valve removes pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a vapor in the evaporator. … Under a greatly reduced pressure the liquid refrigerant is at its coldest as it leaves the expansion valve and enters the evaporator.

Where is the expansion valve located in the home AC system?

The thermostatic expansion valve is usually mounted inline with the tube that supplies liquid coolant to the air conditioner evaporator. The bulb of the expansion valve is mounted to the outside of the output line of the air conditioner evaporator.

How do you remove an expansion valve?

If the valve is all mechanical fittings (no brazing) it should take about 15 minutes, plus the pump down, pressure test,vacuum and recharge. I have changed at least a hundred expansion valves and have never had to pull the coil.

How does a TX valve work?

The Thermal Expansion Valve (TXV) is installed to control the flow of refrigerant into the evaporator in response to the cooling load. TXV’s measure the superheat at the outlet and react to this by increasing or decreasing the amount of refrigerant flowing into the evaporator to try and maintain a constant superheat.

Where is Txv valve located?

What Does a TXV Do? The thermal expansion valve is connected to the smaller line of copper connected to your air handler, either on the inside or the outside of your air handler. It is located right in front of the evaporator coil so it can control the amount of refrigerant flowing into the evaporator coil.