Manitowoc CubeR Runs OUt of Water

Reading Time: 7 minutes

The problem with Manitowoc Technicians and water control issues

The Question: A junior technician submitted the support question below to a senior technician. The problem with the Manitowoc cube ice machine was that it was “running out of water” during the freeze cycle.

Always be aware of the quality of your advice. In this case, the junior tech was being led down the wrong path to solving a simple question.

According to the Senior technician, Manitowoc machines (“always”) commonly have the following problems:

  1. Curtain switch issues.
  2. Bridge thickness sensor issues.
  3. Water level sensor issues
  4. Damaged nickel plating on evap issues
  5. Use tables for expected refrigeration pressure at all stages of operation.
  6. If it is a fault, the codes will flash.
  7. Extended freeze with a big block of ice is a bridge thickness sensor issue
  8. Extended harvest can be a curtain switch issue or a dirty or damaged evap.

However, it is imperative to underscore that the original query explicitly focused on the machine “running out of water” during the freeze cycle. This suggests that while understanding widespread issues is beneficial for a comprehensive diagnostic approach, attention must pivot toward the mechanisms directly influencing water supply and management during the freeze cycle. This could point towards water level sensor issues or potential problems in the water inlet system, both warranting a targeted diagnostic procedure and solution.

The issues described by the senior technician predominantly cover problems related to ice formation and machine sensors without directly addressing the specific concern of the machine running out of water during the freeze cycle.

Given this discrepancy, it raises a few critical questions for clarity:

  • Could the water level sensor issues mentioned indirectly relate to the machine running out of water during the freeze cycle? If so, how does this sensor malfunction contribute to the problem, and what troubleshooting steps should be taken?
  • Are there any additional components not listed that could cause the machine to run out of water? For instance, could there be issues with the water inlet valve or a potential leak within the system?
  • Has regular maintenance and inspection been overestimated in preventing such issues, particularly in relation to water supply components?
  • Do the tables for pressure at all stages of operation provide any diagnostic guidance for issues related to water supply or level during the freeze cycle?

This complex response to a simple question leads to an insightful perspective on why junior technicians might disassemble an ice machine when faced with seemingly simple problems. While thorough, the comprehensive list provided by the senior technician emphasizes a broad spectrum of potential issues without pinpointing a focused diagnostic route for specific problems like the water running out during the freeze cycle. Such an extensive checklist can inadvertently signal to less experienced technicians that a full machine breakdown is necessary to diagnose and rectify issues. Although well-intentioned, this approach might increase the time and complexity involved in troubleshooting and risk overlooking simpler, more direct solutions related to specific components, such as the water level sensor or inlet valve. Consequently, this underscores the importance of targeted training and documentation that guide technicians towards more efficient diagnostic processes, emphasizing understanding machine behavior and component-specific troubleshooting before proceeding to more invasive methods.

Understanding the answers to these questions would provide much-needed clarification and potentially highlight overlooked aspects of the original problem regarding water depletion during the freeze cycle.

The solution to Running Out of Water in a Manitowoc Ice Machine

Explore the reasonable causes for this condition of running out of water in the Manitowoc cube ice machine.

  1. First and foremost, inspect the water level at the start of the freeze cycle. It’s critical to understand that many cube ice machine controllers are programmed to allow a limited amount of time for the reservoir water to top off before locking out further level adjustments. This window is crucial for ensuring the machine has an adequate water supply to complete the freeze cycle efficiently. Failure to achieve the correct water level within this time frame could lead to the machine running out of water. Thus, a preliminary check of the water level at the start of each cycle is indispensable. This approach not only aids in identifying if the issue is due to inadequate initial water volume but also helps determine if the water level sensor is functioning correctly or needs adjustment or replacement.

If the water is correct at the onset, ask yourself, “Where did it go if not the ice?”

  • Issues directly affecting the water level in the cube machine are critical for ensuring efficient operation and ice production. A correct water level at the beginning of the freeze cycle is paramount.
  • Similarly, the purge valve maintains water quality by removing minerals and impurities from the system. If a purge valve is not functioning correctly, it can continuously allow water to drain from the ice machine, causing it to ‘run out of water’ during the freeze cycle.

A machine equipped with a properly functioning purge valve is unlikely to experience siphoning through the drain hose, an issue that can contribute to water depletion during the freeze cycle. Yet, it remains instrumental to periodically check the purge drain to ensure no water leakage is observed. This verification step is essential, as even a minimal, undetected leak could lead to significant water loss over time, impacting the machine’s ability to maintain adequate water levels for ice production.

  1. If an initial assessment reveals that the water level is low at the beginning of the freeze cycle, further investigation into the water filtration devices and building water pressure is necessary. Clogged or outdated water filters can significantly diminish water flow into the machine, necessitating regular checks and replacements according to the manufacturer’s recommendations. Additionally, inadequate building water pressure can impede water flow into the cube machine, thus affecting its ability to maintain a proper water level.

If the water pressure from the filtration system is correct, but the water is not adequately flowing, consider replacing the water inlet valve.

  1. Inspect the water inlet screen for obstruction.
  2. If the water pressure from the filtration system is correct, but the water is not adequately flowing, consider replacing the water inlet valve.


Manitowoc Commercial Ice machine filter installation
Ice machine water inlet valve

Ice machine water inlet valve

Ice machine water inlet valve

Ice machine water purge valve

Ice machine water purge valve

Ice machine water purge valve

Summary For Easy Reading

  • Initial Water Level Inspection: Examine the water level at the start of the freeze cycle to ensure it meets the threshold for adequate ice production.
  • The functionality of the Purge Valve: Evaluate the purge valve’s operation, which removes minerals and impurities and prevents continuous water drainage from the ice machine (siphon).
  • Periodic Check of Purge Drain: Regular inspections are required to identify any leaks that could lead to substantial water loss, which could affect the machine’s ice production capabilities.
  • Assessment of Water Filtration Devices and Building Water Pressure: Investigate any potential reductions in water flow caused by clogged filters or insufficient building water pressure, necessitating routine filter checks and replacements.
  • Inspection of the Water Inlet Screen: Check the inlet screen for obstructions that might impede water flow into the machine. DO NOT remove and discard the screen! The screen protects the water inlet valve plunger from sticking open due to sand, pebbles, and other hard debris.
  • Evaluation of the Water Inlet Valve: If the water pressure is deemed adequate yet flow issues persist, consider the possibility of a malfunctioning water inlet valve requiring replacement.
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