A thermostatic expansion valve plays the important role of regulating the flow of an air conditioner's refrigerant. It ensures that only the required amount of refrigerant flows into the evaporator coil, something that usually goes a long way towards preventing compressor damage. It also helps to ensure that the pressure in the evaporator coil is low enough to ensure an efficient cooling process.
However, there are times when the thermostatic expansion valve malfunctions. In such cases, the efficiency of the air conditioning system usually suffers. It can also lead to air conditioner shutdowns. Here is what you should know about how a malfunctioning thermostatic expansion valve can cause an air conditioner shutdown.
A malfunctioning thermostatic expansion valve and coil icing
When a thermostatic expansion valve gets stuck, or when it gets clogged with dirt, its ability to allow the liquid refrigerant to flow into the evaporator coil is reduced. Its ability to allow refrigerant flow is also affected when it gets frozen or when it is simply defective and can't work as efficiently as it is supposed to.
In such cases, the amount of refrigerant flowing into the evaporator coil will be too little. This will have the effect of causing an abnormal pressure drop in this area. And while the evaporator coil being a low-pressure zone is usually good for the air conditioning process, abnormal drops in pressure are not. This is because abnormally low pressure in the evaporator coil usually result in an extreme temperature drop, something that then causes any moisture in the air passing over the evaporator coil to freeze.
Coil icing and air conditioner shutdowns
The ice that forms over the evaporator coil as a result of the malfunctioning thermostatic expansion valve usually has an insulating effect on the coil. It also presents a problem to the condensate drainage system since when this ice starts to melt, it overwhelms the drainage system with water. This usually causes the condensate collector tray to overflow. And since most air conditioning systems are fitted with a condensate overflow tray, the overflowing water then starts to collect in the condensate overflow tray.
Continued melting of this ice eventually causes this water to rise up the condensate overflow tray and when it reaches a certain level, it triggers the condensate overflow switch. This then causes the air conditioner to shut down.
Replacing your malfunctioning thermostatic expansion valve is an easy way to keep this from happening. It will not only improve the overall efficiency of your air conditioning system, but also save you from the inconveniences of having to do without a functioning air conditioning system. Talk to a professional, like those at Doctor Fix-It, for more information.Share
26 September 2016
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