Covers how to replace a Schrader valve without losing refrigerant by using a specialized removal tool. Explains the step-by-step process and how to manage system pressure during reinstallation.

Walks through how a straight AC system functions, including how the thermostat controls key components like the fan relay, contactor, compressor, and blower. Explains how AC and heat modes differ in operation and which parts activate in each.

Covers how to test and charge systems with a TXV using subcooling. Explains how to calculate subcooling and what ideal ranges indicate about system charge levels.

Explains how to test and charge piston systems using superheat. Covers how to calculate superheat and interpret results to assess refrigerant levels.

Covers brazing techniques for HVAC copper tubing, including bridging holes with silver solder and connecting mismatched pipe sizes by pinching and soldering.

Explains how to safely test a live HVAC contactor, including checking for 240V input/output and 24V control from the thermostat, with strong emphasis on safety practices.

Covers the role of the transformer in converting 240V to 24V to power the thermostat, how the thermostat controls other components, and wiring considerations for universal transformers and emergency use.

Learn how to inspect and maintain HVAC systems during apartment turnovers, including replacing air filters, verifying cooling performance, clearing condensation drains, cleaning coils, and running heat strips to prevent dust buildup and odors.

Learn how to clear hair and debris from tub drains, verify proper drainage, and reinstall stoppers correctly during apartment turnovers.

Learn how to remove old caulk and apply new caulk around sinks, countertops, and painted edges to create a clean, durable seal.