Troubleshooting Safety Limit #2 on Koolaire Ice Machine July 13 2015, 4 Comments

Koolaire ice machines, that shut down prematurely may be turning off due to a safety limit. This article covers the Safety Limit #2 indicator and items to check to help diagnose your ice maker. This feature helps protect your investment, by shutting down the equipment, to prevent damage to parts like the compressor, control board, or evaporator.

What is Safety Limit #2

Safety Limit 2 happens whenever the harvest time exceeds 3.5 minutes for 100 consecutive harvest cycles. It's important to monitor your ice machine and time the harvest cycle, a normal harvest time is around 1.5 5o 2 minutes. Anything longer indicates that it most likely needs to be cleaned or there are other problems, which are outlined below.

Water System

When a Koolaire goes off on a safety limit 2, check the following areas in the water system or circuit. First, make sure the evaporator is clean. Sometimes the only to actually see scale build up on the nickel plated evaporator is for it to be completely dry. Next, make sure you don't have a blocked or dirty dump valve.

After the dump valve, look to see if the vent tube was properly installed for the drain. Next, look for water freezing behind the evaporator or extrusions and gaskets not securely mounted. These things will 'hold' a sheet of ice that has formed on the evaporator from falling properly.

Electrical System

Look to see if the bin switch is defective, by checking the OHM reading.  You need consistency, instead of a constant range of OHMs. Open and close the water curtain, while monitoring the bin switch reading. If at anytime  it's not consistent, replace before troubleshooting other areas of the Koolaire ice maker.

Next, make sure the Koolaire is not attempting to harvest ice prematurely. If the sheet of ice is not properly formed, it may not fall off the evaporator properly. Inspect the evaporator for ice formation during the freeze cycle and then listen and watch for the control board to initiate a harvest. If it's premature, you may need to adjust the harvest float switch or replace.

If you have questions about troubleshooting your Koolaire ice machine, contact Ice Maker Parts Shop at for assistance. Below are refrigeration issues to look for, but we only recommend trained technicians to perform checks on ice maker parts below.

Refrigeration System

Inspect the checklist below for refrigeration parts that may be failing, causing the Koolaire to shut down on a safety limit number 2.

  • non-oem components
  • improper refrigerant charge
  • defective harvest valve
  • TXV flooding
  • defective fan cycling control