In warm regions like Southern California and Los Angeles, air conditioning is a must during the hot summer months. Keeping the interior at the right temperature requires a working thermostat. A thermostat controls the heating and cooling system inside a home. It is designed to detect the temperature inside a room and change it according to the desired thermostat setting. If the room temperature is different from the desired temperature, the thermostat triggers additional heating or cooling depending on the season.
Sometimes the thermostat malfunctions for a variety of possible reasons. If this happens in your case, try troubleshooting your system to identify the possible reason for the malfunction. You may be able to resolve the problem yourself without the assistance of a heating and air conditioning specialist. 
Air Conditioning Won’t Turn On
Make sure the thermostat selector is set for cooling. A built-in timer may delay activation. Check the power source. Go to your fuse box to see whether the circuit breaker has tripped or the fuse has blown. Reset the circuit breaker, or replace blown fuse with another one of the same amperage as needed.
If your system has a breaker panel situated near the outside unit, verify the breaker is on. If the air conditioning system still remains turned off, it may be because the thermostat is set improperly or it has become defective.
Unit Blows Warm Air
Dirty filters may be the reason the system blows warm air. Check your filters. If the filters are not the problem, see if the outside unit is running properly and no debris is obstructing the airflow. Warm air may also be a sign of an insufficient amount of refrigerant. If this is the issue, you will need a licensed technician to replenish the refrigerant.
Your Indoor Temperature Doesn’t Match the Thermostat Temperature
Your thermostat will not regulate temperature properly if it is unable to read temperature correctly. Check to see if the inside of your thermostat is dirty inside. Open its cover and gently remove any dust inside with a soft brush. The thermostat could also be corroded inside. When it is corroded, electrical contacts do not operate properly. You may be able to use an electronic contact cleaner to resolve this problem, or you should consider replacing it.
A Clogged Condensation Line
The drip pan inside a component of the AC system is designed to collect water if the drain line becomes clogged. If water is visible in the pan, blowing compressed air inside the pipe may remove the obstruction. Pour a 50-50 mix of bleach and water into the drainpipe to remove any mold and mildew. Otherwise, ask an air conditioning technician to check the system.
Is a Frozen AC Unit the Problem?
An AC unit freezes for a variety of reasons. One reason is improper airflow. Other reasons include obstructions such as a faulty control relay or a malfunctioning blower fan. Replacing electrical components requires a technician’s assistance.
Is It Time for a New Thermostat?
Regular maintenance checkups prevent most performance malfunctioning issues. Ask your local experienced Los Angeles or San Fernando Valley thermostat technician to perform a maintenance check of your system. Routine maintenance prevents minor problems from becoming major repair issues and keeps the system performing as it was intended to perform. If a maintenance check finds a malfunctioning thermostat is the problem, then you are lucky to escape a major expense!