Manitowoc Ice Machine Troubleshooting

/ Ice Machines, Troubleshooting / January 11

From hotels and hospitals to restaurants and cafeterias, fresh ice is a must, and Manitowoc Ice is one of the best at making it. They manufacture some of the top ice makers in the foodservice industry, ranging from undercounter to standalone S models.

There’s never really a good time for an ice machine to stop working. While it’s not a common occurrence with Manitowoc machines, a couple of issues can pop up occasionally when the unit runs on a daily basis. That’s why we have easy tips for troubleshooting a Manitowoc ice machine, so you can find and solve the problem quickly.

Ice Machine Doesn’t Operate

Possible solutions:


  • Power supply – It’s the one question everyone sighs after hearing: “is the unit plugged in?” Just check. You might be pleasantly surprised that your problem has an easy, cost-free solution.

  • Circuit breaker – Is the breaker tripped or a fuse blown? Check your box for these problems.

  • Toggle switch – If the ON/OFF/WASH switch isn’t set properly, or is somehow stuck between those options, your machine won’t operate. Make sure the switch is set to ON.

  • Damper – If the damper is held open in the down position, the machine will shut off until ice or any foreign obstructions are cleared. The damper must be upright and capable of swinging freely.


Ice Machine Stops, Restarts When Switched Off and On Again

Possible solution:


  • Safety limit – The safety limit on some Manitowoc units is designed to stop the ice machine if there is a possibility of major component failure. Switch the machine off and back on again. If the ice machine continues to run, the condition has corrected itself and you’re good to go! If the machine stops again, the condition requires a service technician.


Ice Machine Not Releasing Ice or Slow to Harvest

Possible solutions:


  • Cleanliness – Clean and sanitize the ice machine.

  • Leveling – Is the ice machine level? Your unit must sit flat on the floor for optimal performance.

  • Ambient air temperature – On air cooled models, the air temperature must be at least 40 degrees Fahrenheit or 4 degrees Celsius.

  • Water regulating valve – On water cooled models, if the water regulating valve is leaking in harvest mode, it could cause a problem. Replace the valve.


Ice Machine Doesn’t Cycle Into Harvest Mode

Possible solutions:


  • Timer – The harvest sequence cannot be initiated until a 6-minute freeze timer has elapsed. If ice forms before then, it will be held until the timer completes.

  • Ice thickness probe – Is the probe dirty or disconnected? Does the ice thickness probe need adjustment? The water flow, not the ice, should contact the ice thickness probe to initiate harvest.

  • Uneven ice fill – If the ice is thin at the top of the evaporator, continue reading for the solution further down in this post under the problem “shallow or incomplete cubes.”


Ice Quality is Poor, Soft or Not Clear

Possible solutions:


  • Water quality – If your water quality is poor, there are many potentially expensive problems that can occur. Contact a qualified service company to test water quality and for the right filter recommendations.

  • Water filters – If you already have a filtration system, your water filter may need replacing.

  • Cleanliness – Lime scale can cause poor ice quality. Clean and sanitize your machine.


Shallow/Incomplete Ice Cubes or Ice Fill Pattern Incomplete on Evaporator

Possible solutions:


  • Ice thickness probe – See if the ice thickness probe need adjustment.

  • Water level – Make sure the water trough level isn’t too high or too low.

  • Water temperature – Ice machines require a cold water supply. Make sure there is not a hot water supply line into the machine.

  • Filtration – The water filter may need to be replaced.

  • Water pressure – The water pressure into the machine must be 20-80 psi (137.9-551.5 kPA).

  • Water float valve – Check the water float valve’s filter screen, as it may need cleaning, and clean the water float valve itself. Both can cause an issue with shallow or incomplete ice cubes.

  • Leveling – Make sure the machine is level. The machine must sit flat on the floor for optimal performance.


Low Ice Capacity

Possible solutions:


  • Water supply – Is the water supply connected? Make sure the water service valve is open.

  • Water float valve – Check the water float valve’s filter screen, as it may need cleaning, and clean the water float valve itself. Both can cause low ice capacity.

  • Condenser – Make sure the condenser is clean and free of obstructions, especially in air-cooled models.

  • Air temperature – The air temperature must not exceed 110 degrees Fahrenheit (43 degrees Celsius) in air-cooled models.

Not finding the answer to your troubleshooting question? Check out our collection of Manitowoc Ice machine manuals to assist you.


Leave a Comment