First, let me say that 9 out of 10 callbacks on a new unit are related to the machine not being installed according to the factory specs. This problem is no exception. When we receive calls about this problem the solution usually lies in the external drain circuit. When installing a Hoshizaki ice machine, the technician should refer to the Instruction Manual that comes with the machine. You can also find information on installation in the Hoshizaki Technician’s Pocket Guide.
All Hoshizaki icemakers require a dedicated ¾” ID drain for the reservoir. This can be plumbed using either copper or PVC. On KM’s that use water cooled condensers, the outlet of the condenser should be ½” and piped separately from the sump drain. On all Hoshizaki KM units manufactured after 1988, the unit will start in the one-minute fill cycle. Within 60 to 90 seconds you should see water coming from the sump drain. This will assure us that the unit has good water volume to the machine. During the harvest cycle the water valve will remain open. This water is used to flush the bottom portion of the sump. The water coming in will help agitate the minerals that lie at the bottom of the sump tank and flush them down the drain.
Now we will address the problem, because of the flushing action in the harvest cycle, it’s important that the reservoir drain not be smaller than the required ¾”. The drain should also be vented; this is typically done using a tee at the back of the unit. The unit drain should never be tied in with the bin drain. Proper plumping practices should be followed when running the drain line to the floor drain.
The two items that most often cause this problem are:
To find out where the restriction lies, cut the drain about 12” below the vent tee and place a 5-gallon bucket to catch the water during the harvest cycle. If the water stops overflowing inside the bin, the restriction is further down the external drain system. If the problem still occurs, then the restriction may be in the machine, between the standpipe and the drain outlet. Slime or other build up normally causes this type of restriction in the drain. You can usually blow nitrogen or CO2 through the drain to clear the restriction. If this restriction is found to be slime or algae build up the entire machine should be cleaned and sanitized. I hope that these suggestions will help you solve the problem of the reservoir overfilling and water falling into the bin.
By Hoshizaki America Support