Troubleshooting Ice Machines

To help explain how to troubleshoot these issues, we’ve consulted with Nestor Moscoso at B&G Refrigeration in Jacksonville, Florida.  Nestor is a seasoned commercial refrigeration expert who graduated HVAC refrigeration school in 1965. His extensive career includes more than 50 years of hands-on commercial refrigeration experience. He also taught commercial refrigeration and air conditioning at the Tulsa Welding School in Jacksonville.

TROUBLESHOOTING POOR QUALITY OF ICE FROM AN ICE MACHINE

Symptoms:

• Air bubbles in ice cubes.

• Ice cubes may be cloudy or not crystal clear.

Causes: Moscoso said, “The most common cause for imperfect ice is bad water quality coming into the ice machine. The majority of complaints ice machine owners have about their ice machines stem from using water with impurities.”

Water impurities typically include lime (limescale), calcium, and fluoride. When these impurities are run through an ice machine, it can slow the production of ice and diminish the quality of the ice produced.

Additionally, scale and calcium can build up on the ice machine’s evaporator and on other components in the ice machine. Eventually, calcium and lime buildup can contribute to premature failure of parts on the ice machine.

Solutions: Moscoso said, “There is no perfect solution for poor water quality. You can only hope to slow the problem down through advanced water filtration and water softeners. Technicians may thoroughly clean an ice machine and install a multi-stage water filter to help reduce the negative effects of poor water quality. Regularly scheduled maintenance is also important. It may also be a good idea to suggest hiring a water company to test the water at the ice machine’s location and implement their recommended water filters.”

TROUBLESHOOTING IRREGULAR ICE CUBE SHAPES

Symptoms:

• Ice is too small, thin, or thick.

Moscoso said, “Many factors may affect an ice machine’s production of ice. Before troubleshooting anything, it is important to know and understand the specific ice machine’s sequence of operation. You cannot troubleshoot without knowing the sequence of operation for a particular make and model of ice machine. Technicians should consult with the ice machine’s manual if they are not familiar with the ice machine’s sequence of operation. ”

Causes:The cause for irregular ice cube shapes from an ice machine can vary based upon the brand of ice machine. Each ice machine manufacturer may use slightly different sensors and methods for making ice. We’ll examine scenarios where there is adverse ice production from two of the industry’s top ice machine manufacturers — Manitowoc and Hoshizaki.

1. Troubleshooting Manitowoc Ice Machines — Moscoso said, “Manitowoc ice machines typically dump ice every 25-35 minutes. If the ice is too thick or thin after 25-35 minutes, there is likely a problem with the sensor.”

Solutions: He advises technicians to check the light on the control board to determine if water is touching the sensor properly. According to Moscoso, water should touch the sensor for at least 33 seconds for Manitowoc ice machines.

He said, “Manitowoc sensors must be 1/8^th of an inch from the evaporator. The bridge should also be about 1/8^th of an inch. Technicians may need to adjust the sensor by screwing it in or out to ensure it is configured properly.”

He also warns to be careful not to screw the screw too far in. The sensor may be easily damaged if the screw is set too far in.

2. Troubleshooting Hoshizaki Ice Machines — Moscoso said, “Hoshizaki ice machines are controlled by water flow through a float valve. If the ice is too thin or thick, there is likely a problem with the float valve or standing pipe.”

Hoshizaki float valves use a magnetic switch to tell the ice machine to produce ice once the sump is filled up.  Moscoso described how float valves may become dirty over time, and the float may either stick to the top or bottom. A stuck float would negatively affect ice production and may create imperfect ice.

In addition, Hoshizaki ice machines use a standing pipe to clean the sump of contaminants after ice production. If the standing pipe is dirty or not installed properly, it may adversely affect ice production.

Solutions: Moscoso said, “Technicians should ensure the float valve is clean, not sticking, and free from cracks. The float vent must also be clean and unclogged so the float valve may function properly.”

He added, “Make sure the standing pipe is clean and the cover is on. Water will drain prematurely if the standing pipe cover is not on correctly. In addition, contaminants may build up over time in the water if the standing pipe is not clean and draining properly.”