If they are blowing instantly as soon as the unit tries to start that usually indicates a defective compressor. If they only blow once in awhile that could be a number of things and would require a competent ac tech to have a look at it to determine and repair the cause.
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The most common problem would be a lack of the coolant in the A/C unit. The other would be a broken condenser.
$10-$15
A supply duct connected to the return duct somewhere? Fan running backwards?
A "hard start kit" is a start capacitor, wired in with the compressor motor, to help it start on a call for cooling.
Typically if you are getting hot air you need to recharge your freeon(spelling). It is something that can be done at home, but i strongly encourage professional charging.
no electricity
This could be due to a refrigerant leak, a malfunctioning compressor, or a clogged air filter, which can restrict airflow. It's best to contact a professional HVAC technician to diagnose and repair the issue.
Most likely there is an electrical short somewhere in the system, check the wiring.
The first air conditioner for the home was available in 1928 when Willis Haviland Carrier developed the 'Weathermaker', an air conditioner for private home use.
Control center