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Tips, tricks and essentials for restaurant and foodservice equipment in one place.

Manitowoc Ice Machine Troubleshooting


There’s never really a good time for an ice machine to stop working. While it’s not a common occurrence, issues can pop up occasionally when the unit runs on a daily basis. That’s why we have this Manitowoc Ice machine troubleshooting guide to help you identify and resolve issues quickly and easily.

These troubleshooting instructions are for popular modes like Indigo NXT, Flake and NEO series machines. For a list of common fault codes and what they mean, refer to our Manitowoc Ice machine error codes article.

Not Making Ice or Making Low Amount of Ice

  • Disconnected water supply – Is the water supply connected? Make sure the water service valve is open.
  • Water float valve – See if the water float valve and its filter screen are dirty. Either can cause low ice capacity.
  • Condenser is dirty – Make sure the condenser is clean and free of obstructions, especially in air-cooled models.
  • Air temperature is too high – The air temperature must not exceed 110 degrees Fahrenheit (43 degrees Celsius) in air-cooled models.

Ice Machine Doesn’t Operate

  • No power – 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.
  • Tripped circuit breaker or blown fuse – Is the breaker tripped or a fuse blown? Check your box for these problems.
  • Toggle switch isn’t on – 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 is open – 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

  • Safety limit is triggered – 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, an authorized service technician will need to repair the issue.

Slow or Long Harvest / Not Releasing Ice

  • Dirty machine – A dirty machine can slow down the harvest cycle or impede ice from releasing. Clean and sanitize the ice machine following the instructions in the owner’s manual.
  • Machine isn’t level – Is the ice machine level? Your unit must sit flat on the floor for optimal performance.
  • Ambient temperature is too warm – On air-cooled models, the air temperature must be at least 40 degrees Fahrenheit or 4 degrees Celsius. Make sure the room isn’t too hot.
  • Water regulating valve leaking – On water-cooled models, if the water regulating valve is leaking in harvest mode, it could cause a problem. Replace the valve.

Ice Machine Not Harvesting

  • Timer hasn’t stopped – 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 dirty or disconnected – Clean the probe if it’s dirty. If the ice thickness probe needs adjustment, make sure it’s adjusted so the water flow contacts the probe to initiate a 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

  • Poor 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 are broken or dirty – If you already have a filtration system, your water filter may need replacing.
  • Dirty machine – Limescale can cause poor ice quality. Follow the manufacturer’s instructions to clean and sanitize your machine.

Making Hollow, Shallow or Incomplete Ice Cubes

  • Ice thickness probe out of adjustment – See if the ice thickness probe needs adjustment.
  • Water level is too high or low – Make sure the water trough level isn’t too high or too low.
  • Water temperature is too high – Ice machines require a cold water supply. Make sure there isn’t a hot water supply line into the machine.
  • Water filter is broken – The water filter might be too dirty or damaged. You’ll need to replace it.
  • Water pressure is too low – The water pressure into the machine must be 20-80 psi (137.9-551.5 kPA).
  • Water float valve – See if the water float valve and its filter screen are dirty. Either can cause shallow or incomplete ice cubes.
  • Machine isn’t level – Make sure the machine is level. The machine must sit flat on the floor for optimal performance.

Ice Machine is Leaking Water

  • Faulty or broken water pump – If the leak is coming from the inside of your ice machine, one cause can be a broken or faulty water pump. Have an authorized service technician check it out.
  • Cracked or loose water lines, pipes or tubing – Check the water lines and pipes if you find a water leak. This could mean that the water line is damaged or worn, or the connection is loose.
  • Faulty or broken water inlet valve – The water inlet valve allows the ice machine to control the amount and flow of water to make ice, and if it’s broken or faulty, it may need to be replaced by a service tech.
  • Clogged drains –  A clogged drain means your ice machine can’t drain correctly and will cause an overflow. Make sure there isn’t any debris on or surrounding the floor drain or the main drain line to your ice machine.

Ice Thickness Probe Issues on Ice Machine

Sometimes the cause of an issue in your ice machine can be the ice thickness probe. If your ice machine is making oddly-shaped ice or it just doesn’t want to harvest, it could be your ice thickness probe. Here’s what to look out for when checking your ice thickness probe.

  • Damage, cracks or bulging – If you notice anything unusual, like damage or bulging, call your authorized service technician to check out the ice thickness probe
  • Ice-Bridge Thickness – The ice-bridge thickness is factory set to 1/8 inch (3 mm). If the thickness is off, use the adjustment screw on the ice thickness probe to change the ice-bridge thickness. Turn the screw clockwise to increase the thickness and counterclockwise to decrease the thickness. Also, remember that:
    • 120-degree (1/3 revolution) turn = 1/16 inch (1.5 mm) of adjustment
  • Probe should swing freely - Check to make sure the wire isn’t restricting its movement.

If you’re still searching for help, check out our collection of Manitowoc Ice machine manuals. Don’t own a Manitowoc machine? Look through our general commercial ice machine troubleshooting guide for assistance.

Please contact a local service company who can help with these specific units and all your home appliance needs.