Why Don’t People Do This Before Calling an HVAC Tech?

Summary by Krater

A DIY guide on how to troubleshoot and fix an HVAC air conditioning system that is not cooling, using a multimeter and simple checks for thermostats, water indicators, fuses, wiring, breakers, filters, condensers, and capacitors.

From the video

Answers: How do I troubleshoot and fix my AC when it's not cooling?

• HVAC troubleshooting
• Thermostat troubleshooting
• Multimeter voltage testing
• AC capacitor testing and replacement
• AC condenser coil cleaning
• Air filter replacement

What it concludes

• A blank thermostat screen can often be fixed by simply replacing its AA batteries.
• A healthy thermostat voltage reading should be between 24 and 28 volts AC.
• A proper Delta T (the difference between return and supply air temperature) should range between 16 and 22 degrees Fahrenheit.
• Flickering the AC service disconnect box off and back on can sometimes reset the system.
• Dirty outdoor condenser coils reduce cooling efficiency and lower the Delta T.
• Testing a capacitor with a multimeter is the best way to determine if a bad capacitor is causing the AC not to cool.