CFESA Repair Techniques 2

Question 1

When replacing a gas valve on a commercial range, what must be verified after installation before returning the unit to service?

Accepted Answer

Leak test all connections with approved soap solution and verify proper outlet pressure

Answer

After replacing a gas valve, all connections must be leak-tested and outlet pressure verified to ensure safe, correct operation.

Question 2

A commercial convection oven's blower motor runs but the fan blade does not spin. What is the most likely cause?

Accepted Answer

Sheared motor shaft key or set screw

Answer

If the motor runs but the blade does not spin, a sheared key or loose set screw has disconnected the blade from the shaft.

Question 3

Which technique is used to identify a cracked heat exchanger in a commercial gas fryer?

Accepted Answer

Pressurize the heat exchanger with nitrogen and check for bubbles in the oil

Answer

Pressurizing the heat exchanger with nitrogen and submerging or coating with soap solution reveals cracks through bubble formation.

Question 4

When soldering refrigerant tubing on a commercial ice machine, which gas should be flowed through the tubing to prevent internal oxidation?

Accepted Answer

Dry nitrogen

Answer

Flowing dry nitrogen through refrigerant tubing during soldering prevents copper oxide scale formation inside the lines.

Question 5

A steam kettle is producing insufficient steam pressure. After confirming adequate water supply, what is the next diagnostic step?

Accepted Answer

Check and clean the steam generator scale buildup and inspect the safety valve

Answer

Scale buildup in the steam generator reduces heat transfer efficiency, and a faulty safety valve can bleed off pressure before it builds properly.

CFESA - Commercial Food Equipment Service Association Practice Test