What tool is essential for monitoring electrical issues in HVAC systems?

A multimeter is essential for monitoring electrical issues in HVAC systems due to its ability to measure various electrical parameters, including voltage, current, and resistance. This versatility makes it invaluable for diagnosing problems such as shorts in wiring, checking voltage at components, and confirming that motors and other electrical devices are operating within their specified ranges.

For instance, if there is no power to a component, a technician can use a multimeter to measure incoming voltage at the device to confirm whether the issue is upstream or localized. This information allows for efficient troubleshooting and repairs, ensuring that the HVAC system functions safely and effectively.

The other tools listed, such as a thermometer, manifold gauge, and leak detector, each serve specific purposes. A thermometer measures temperature, a manifold gauge is used for checking refrigerant pressures, and a leak detector identifies refrigerant leaks. While they are important for certain HVAC tasks, none of them provide the comprehensive electrical testing capabilities that a multimeter does.