Title: Identify the components of each alternative system.
Course: Heating, Ventilation, Air Conditioning, and Refrigeration II (17056-II) > Section: Servicing and Maintaining Alternative Fuel Heating Systems

Identification should include the major components for the following systems:

- Electric—the element, sequencer, limit switch/control
- Heat pump—reversing valve, defrost control
- Hydronics—water or circulating pump, isolation valve, expansion tank, zone valve, pressure-reducing valve

Process/Skill Questions:

- How is electric heat measured?
- What is the function of a reversing valve?
- What are the sequences of the defrost cycle?