tells the system to cool or heat. a common central a/c problem results from the the thermostat not set to “cool” and / or the thermostat is not set lower than the indoor temperature.
shown: the 3-position switch is located on the lower right corner of thermostat above. “cool” will be on one side. “off” in the center, & “heat” on the other side.
note: there is another switch for the (blower) fan. it shows “auto” & “on” settings — leave it set to “auto” year round.
clogged drain line one of the most common central a/c problems is a clogged drain line for the removed humidity. as your a/c runs, air is 