i have a manitowoc MOD-QD133W Ice machine after cleaning it will only make small ice cubes, even after adjusting it.

[techjoeb]

So after cleaning the ice machine it will only make small cubes? It sounds like something is misaligned. There are only two reasons that I can think of the unit harvests prematurely, if the thickness sensor is feels it’s time to harvest or the main board is fried and doing wacky things. Unless you got the main board wet during the cleaning I’m thinking your thickness sensor may be  misaligned. Also make sure water isn’t splashing on the sensor. Sometimes after cleaning the water tray isn’t in all the way or installed incorrectly causing water to splash on the thickness sensor and causing it to harvest prematurely. I can’t find specs or info  on that model. Please check the model again. Tell us what the issue is of you find a solution.

 

-Joe 

[john]

I believe the customer has a Manitowoc Ice QD0133W. 

This is a water cooled unit.

 

Here’s the owner’s manual for the QD0133 http://download.partstown.com/is-bin/intershop.static/WFS/Reedy-PartsTown-Site/-/en_US/manuals/MAN-Q-Under-Counter-Serie… 

And the service manual: http://download.partstown.com/is-bin/intershop.static/WFS/Reedy-PartsTown-Site/-/en_US/manuals/MAN-QM-SM-Q-Series_sm.pdf 

 

I wrote a short general troubleshooting guide for Manitowoc Ice machines here: Manitowoc Ice Machine Troubleshooting | Parts Town 

There’s a section in the above guide about shallow/incomplete ice cubes. I hope it’s useful!

 

-John

[fixbear]

First off, this is a water cooled under-counter machine. As a Guest, you will not see our post and answers unless you join the group.

Did you remove and clean the water distribution tube at the top of the evaporator?  It’s common for a piece of calcium to partially block a port and cause irregular flow so that the ice sensor trips early. Also during cleaning one has to remove and clean the ice thickness probe. It also has to be rinsed and dried so that there is no cleaning solution left on it. Otherwise the plastic base becomes conductive when damp.

   Did you disturb the water siphon or it’s cap. If so the water level may be low and the pump sucking air causing spray at the sensor.Or adding to much water requiring heat rejection beyond capacity. Machine then goes to max ice time harvest and sets a code. Check the pump line as well.

   Incoming water filtration may not be functioning and causing a premature harvest.

 

This machine locks into freeze for 6 minutes before it monitors the thickness sensor. Once the probe has continuous conductivity for 7 seconds the goes into harvest. You can monitor the prode with the lower LED on left side of the control board.

[ectofix]

I’ll add that the ice thickness control (that sensor hanging in front of the evap plate) isn’t impervious to failure.  Although it seems a simple enough device, I’ve had arguments with many that have been in service awhile.  By arguments, I mean that no matter whether I’d cleaned (delimed/sanitized) them, repeatedly adjusted them and then awaited the results of the next harvest, the board’s LED would tell me it’s sensing water when the ice bridge isn’t even close yet.

 

A baseline adjustment is to use the flats of a 3/16″ Allen wrench to measure clearance and, using the set screw, set the probe there.  You want 1/8″ bridge thickness.  Monitor the harvests and tweak the set screw in or out accordingly to get that bridge right.

If it seems to not give you consistently expected results…or the ones that you desire, replace it.

 

What I’m getting at is that, in my experience, if desired quality of ice production can’t seem to be achieved, replace the ice thickness control and be done with the problem.