Skip to content
C-20 Silver Bundle

CSLB HVAC (C-20): Study Guide and Online Practice Exam

$250.00 $300.00 Save $50.00

What’s included


What this covers

Per the state's classification, a C-20 contractor installs, services, and repairs forced-air heating, ventilating, and air conditioning systems, including ductwork, equipment, and refrigeration components. This printed book covers the subjects the state tests. See the official CSLB C-20 classification.


Sample questionsTry our free practice test

  1. In 1 ton of air conditioning there are how many Btu's per hour?
    A. 10,000 · B. 11,000 · ✓ C. 12,000 · D. 15,000
  2. Two methods of evacuation are:
    A. Deep and purging · B. Deep and vapor · ✓ C. Deep and triple · D. Deep and surface
  3. The mechanism that comprises both a service valve and a pressure gauge is a:
    A. Selenium · B. Charging pulse · ✓ C. Testing manifold · D. Transformer
  4. A three pipe water system has which of the following?
    A. 1 return, 1 supply and 1 reserve · B. 1 supply, 2 returns · ✓ C. 2 supplies, 1 return · D. 2 returns, 2 supplies
  5. A compressor in which compression is attained in a cylinder by rotation of a semiradial member is known as which of the following?
    A. Compressor · ✓ B. Rotary compressor · C. Hermetic compressor · D. Open type compressor
  6. Which of the following describes series heating cooling circuits?
    A. Single circuits · ✓ B. Combination circuits · C. 3 way circuits · D. 4 way circuits

California contractors who passed

The timer was my biggest problem. Practicing with the clock running taught me not to stay too long on one question.

Vince Los Angeles, CA  · HVAC (C-20)

Simple and clear, and the system drawings are easy to follow. I studied for two weeks and passed on my first try.

Grant Palm Desert, CA  · HVAC (C-20)

I studied with my phone on my breaks. Passed my HVAC exam the first time.

Cesar Maywood, CA  · HVAC (C-20)