The ice thickness control goes by a number of names, like an ice thickness probe or harvest switch.  Essentially the Manitowoc ice thickness control will serve 2 functions.  As the first name suggests it will control the bridge thickness of the ice and it tells the ice maker when to go into harvest.  In most Manitowoc ice makers the ice thickness control is the only thing that will tell the control board to terminate the freeze cycle and initiate a harvest mode.

The most common ice thickness control is a single wire probe.  All Q, J, and B Series ice makers will use the same probe, a part number 7627813.  The newer S Series Manitowoc ice machine also uses a single wire probe, however the newer ice thickness control has a longer plastic base and is not interchangeable.  The part number for an S Series ice thickness control is 200802.

Ice thickness or bridge thickness can be set by turning a screw located on the ice thickness control.  This physically moves the metal part of the probe closer or further away from the ice maker evaporator.  By moving the probe further away from the evaporator the bridge on the grid will actually become thicker, before going into a harvest mode.  Manitowoc's ice thickness probe on S Series and older ice makers used continuity to tell the board when it was time to harvest the ice.  After 6 continuous seconds of contact with water, the board will then initiate a harvest cycle.

Most commonly the ice thickness control will fail due to being dirty.  Scale build up will cause the ice maker to go into a premature harvest cycle and attempt to harvest when no ice or little ice has formed.  It's possible to simply clean the probe and re-install.  Use Caution, a soft nylon brush is all that is recommended to scrub on the plastic and metal parts of the control, scarring will also ruin the probe.

New for 2011, from Manitowoc, is the Indigo ice maker which features a newly designed ice thickness control.  The ice thickness control for the I Series ice maker uses sonar to sense the bridge thickness of the ice and no longer looks for contact with water.  This will improve the life of the ice thickness control and cut down on how often it needs to be cleaned.  Unfortunately there is no retro fit kit for the new ice thickness control to work on older style Manitowocs.

New Indigo Ice Thickness Control, Part Number 000008660 available now!