Wi-Fi models can be controlled from a mobile device or computer remotely. Considering all of the options available, there are a number of ways your thermostat settings can make it appear that your air conditioner is not running correctly. Symptoms you might notice include:* Slightly warm air blowing from the registers/vents（风口）at times，and cold air blowing at other times*Higher than expected temperature reading on the thermostat*No air blowing from the registers/ventsIf you experience any of the above symptoms in your home, be sure to check the thermostat before calling a repair service.*Is the thermostat set for heating instead of cooling the air? If it is,simply adjust the thermostat so it is set to cool, or change the setting to auto so it will automatically change between cooling and heating as temperatures change.*Check the temperature setting to make sure somebody else didn't change it to a higher setting.To solve problems of an air conditioner,you should first____

Knowing how to troubleshoot an air conditioner often starts with the main control—its thermostat（恒温器）.Thermostats come in a variety of options，starting with very basic models that simply control heating and cooling temperatures and fan operation.Programmable（可程控的）models can be set to automatically change temperatures throughout the day for better comfort when you are home, and higher efficiency when you are at work or asleep at night. Wi-Fi models can be controlled from a mobile device or computer remotely. Considering all of the options available, there are a number of ways your thermostat settings can make it appear that your air conditioner is not running correctly. Symptoms you might notice include: * Slightly warm air blowing from the registers/vents（风口）at times，and cold air blowing at other times *Higher than expected temperature reading on the thermostat *No air blowing from the registers/vents If you experience any of the above symptoms in your home, be sure to check the thermostat before calling a repair service. *Is the thermostat set for heating instead of cooling the air? If it is,simply adjust the thermostat so it is set to cool, or change the setting to auto so it will automatically change between cooling and heating as temperatures change. *Check the temperature setting to make sure somebody else didn't change it to a higher setting. To solve problems of an air conditioner,you should first____　　

• A. read its user manual　　
• B. check its thermostat　　
• C. call a repair service　　
• D. turn off the air conditioner