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Turns Off Abnormally - Window or Through the Wall AC

Troubleshooting Air Conditioners Last Updated 06/23/2018
Turns Off Abnormally - Window or Through the Wall AC

If the air conditioner powers turns off abnormally, follow the steps below to resolve the issue. For other related power power issues, please visit Power Issues - Room Air Conditioner article.

  1. Are there any items nearby to the AC unit that are obstructing air flow?

    obstructed unit
  2. Move plants or curtains that will block airflow area from the front grill of the unit. The unit must also have enough room in the back for the exhaust to dissipate in order to work effectively. Blocked air flow could cause the unit to overheat and shut down during normal operation.

    blocked unit
  3. Have the air filter and coils been cleaned?

  4. We need to check for POWER LOSS on your unit, click the button below to proceed to the POWER LOSS section.

    Proceed to Power Loss
  5. The air filter should be cleaned once every two weeks and the coils should be checked periodically for dust buildup. Dirty air filters or coils will restrict airflow which will reduce cooling performance. Also this may restrict airflow enough for the unit to overheat and cause the unit to shut down during normal operation.

    Evaporator Coils

    • Remove the front grill.

    • Use a brush attachment with a vacuum cleaner to clean up any dust or debris that has made it past the air filter.

    • If you are cleaning the coils after the air conditioner has already been running, put the unit in fan mode for about an hour in order to allow any condensed moisture on the evaporator coils to dry.

    Condenser Coils

    • Use a soft bristled brush to gently brush the condenser coils while rinsing them off with a water hose pipe.

    • Remove any garden sprayer attachments and allow the water to flow directly from the end of the hose down over the coils to wash away dirt and debris.

    • The brush will loosen any build up that may have dried onto the coils.

    NOTE: The fins are sharp so take care when cleaning them. Do NOT bend the fins. If this happens accidentally you can purchase a fin comb from a local hardware store. The fin comb can be used to straighten any bent fins.

    For full maintenance information about your specific model, refer to your owner's manual for detailed information. Please visit our Manuals and Documents page to download a copy.

  1. Does the unit completely lose power (completely unresponsive to controls) or just stop running?

    Completely Loses PowerJust Stops Running
  2. Sometimes, when the air condition loses power, it causes the home's circuit breaker to trip. Let's check the next section for further troubleshoot.

    Proceed to Breaker Trip
  3. If the unit simply stops running, this could be the result of the unit being in the wrong mode of operation. Check the control panel to see what mode the unit is currently operating.

    Set Unit to Cool Mode

    Press the mode key on the panel until COOL is selected. You may need to adjust the TEMP setting keys to a temperature setting lower than the current room temperature.

    Dail Type Controls

    Make sure the dial is set to COOL, and raise it to a higher cooling level (higher number).

  1. Does the breaker trip off when the unit loses power?

    Yes, breaker tripsNo, Check AFCI
    • Turn off all other electrical devices in the room besides the air conditioner.

    • If the unit runs fine with other devices turned off, then likely the unit is not on a dedicated circuit breaker.

    • If the unit is not on a dedicated circuit breaker, the unit may power on but not run.

      The reason for this is the unit does not require as much power to display the settings, or even run the fan, as it does to turn on and run the compressor. The A/C must be on a dedicated circuit breaker and not share with other outlets.

  1. Was the power lost because the AFCI (arc fault circuit interrupter) tripped on the power cord?

    Yes, AFCI is TrippedNo, AFCI hasn't Tripped afci power cord
  2. Most newer models will have a green LED indicator light on the back of the power cord. If the green light is not illuminated, then press the RESET button on the power cord to restore power.

    NOTE: The AFCI device should be tested on a periodic basis by first pressing the TEST button and then the RESET button. If the TEST button does not trip or if the RESET button will not stay engaged, discontinue use of the air conditioner, it will require a repair service, please visit our Request a Repair page.

  3. If the AFCI hasn't tripped and the unit still will not power on, the unit will require a repair service. Please visit our Request a Repair page.

Author - Sanmi Ajanaku

Sanmi is a Home Appliance expert and author of this help library article. Please leave him feedback below about the page.

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