Window and room air conditioners use a lot of electrical energy, which can lead to less than maximum efficiency or even a total failure.

1 Make sure the device is plugged in and the switch is on. Make sure the thermostat is set to "cold" and below room temperature.

2 Make sure the electrical outlet works with a voltage tester or by plugging in a working lamp (only for standard voltage models - don't plug a lamp into a 220/240 volt socket!) To learn more about testing a socket,…