Diagnosing a Sealed Window Air Conditioner Unit for Low Refrigerant

By | January 7, 2023

Diagnosing a Sealed Window Air Conditioner Unit for Low Refrigerant
While not common, repairing window air conditioner units can be done, including checking for low refrigerant and adding some if necessary.

Since sealed units don’t have a service port for gauges, checking if it is low on refrigerant is not as quick as other HVAC systems.

Installing service ports can be done and is not a difficult job, but some basic things can be done first.

Using an Amp meter and an IR temperature gun, we can quickly tell if there is no refrigerant flowing inside a sealed system.

Methods for Diagnosing a Sealed Window AC Unit for Low Refrigerant

  • Method #1 Use an Amp Meter
  • Diagnosing a Refrigerator Sealed System Problem using an Ammeter
    Most small compressors installed in window units or similar will run around 2 Amps. Of course, check the faceplate to be sure what amps it uses.

    If the compressor is not working and pumping refrigerant in the system, the amps will be much lower compared to the standard amp usage.

    For example, a compressor that regularly uses 2-Amps will be using 1-Amp or lower.
    Diagnosing a Refrigerator Sealed System Problem using an Ammeter and a IR Temperature Gun
    Of course, the compressor does not always run and shut off and on, so be sure the temperature is set lower for the unit to kick on.

    If the amps are low, it does not automatically make the compressor bad, but it does point to the fact that refrigerant is not flowing in the system for whatever reason.

    For example, a unit could have a leak.

  • Method #2 Using an Infrared Temperature Gun
  • An IR temp gun (or any thermometer) can be pointed at the condenser to see the amount of heat it is giving out.
    Diagnosing a Refrigerator Sealed System Problem using a IR Temperature Gun

    Most condensers will run around 100 degrees, so if it is lower, there is likely a problem.

    Of course, be sure the condensing fan motor is running, pushing air through the coils, and dissipating the hot air.

    The above method is just some simple things to quickly check when you approach a sealed HVAC system and want to see if there is refrigerant flowing.

    There are no doubt many other methods that can be used to troubleshoot a unit.

    Some things will even be obvious such as the noise the compressor is making on the window unit.

    If in doubt, installing a service port to hook up gauges is an easy job with the right equipment and can be done easily.

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