Quick answer: Clean and sanitize a Manitowoc ice machine at least every six months, and more often on hard water or heavy use. Manitowoc also sets a lower limit: do not clean more often than once every two months, because the cleaner is corrosive. It is a two-step job: Manitowoc Ice Machine Cleaner to strip mineral scale, then Manitowoc Sanitizer to kill mold and slime. They are different chemicals and both are required.
A Manitowoc ice machine needs a full clean and sanitize on a schedule, not just when the ice looks off. Manitowoc calls for it at least twice a year, and more often where the water is hard or the machine runs hard, using two Manitowoc-approved chemicals that do different jobs. That schedule is also a food-safety line: the FDA Food Code treats the machine interior as a food-contact surface that has to stay “clean to sight and touch.”
Key facts
- Interval: at least every six months, and more often on hard water, high volume, or a hot back-of-house. Never more often than once every two months, which is the lower limit Manitowoc sets.
- Hard water is the trigger: the USGS classifies water at 121 to 180 mg/L as calcium carbonate as hard, which is roughly 7 to 10.5 grains per gallon. Manitowoc publishes no hardness threshold of its own, so have the water tested and set the interval from the result.
- Two chemicals, two jobs: Manitowoc Ice Machine Cleaner strips scale, then Manitowoc Sanitizer kills biofilm. Never mix them.
- Use only what Manitowoc approves. The evaporator is nickel plated, and Manitowoc warns that a descaler or sanitizer of another brand can cause damage that is “not covered under the warranty.”
- Discard the first full batch of ice after the clean.
Why do you need both a cleaner and a sanitizer?
Use both, in order, and never mix them. The cleaner is an acid that removes mineral scale and lime. Scale insulates the evaporator, so a scaled machine makes less ice and runs longer to do it. The sanitizer is a disinfectant that kills the biofilm scale leaves behind. Skip the sanitizer and the slime stays. Skip the cleaner and the scale stays, and the slime clings right back to it. Use only nickel-safe ice machine cleaner, and wear gloves and eye protection. Of the two, operators skip the sanitizer most, and it is the one that keeps the pink and gray slime from coming back. That slime is biofilm, a living mix of bacteria and mold whose pink tint is usually Serratia marcescens, and it carries a real contamination risk: is mold in an ice machine dangerous?
How often should you clean a Manitowoc ice machine?
Every six months is the floor. Shorten the interval if the water is hard, if the machine runs at high volume, or if it sits in a hot back-of-house, but do not clean more often than once every two months. Manitowoc is explicit that a cleaning interval shorter than two months must be avoided, because the cleaner is corrosive. The USGS classifies water at 121 to 180 mg/L as calcium carbonate, roughly 7 to 10.5 grains per gallon, as hard, so have the water tested rather than guessing from how the ice looks. An Indigo NXT will post a cleaning reminder on the display, but the reminder is a prompt, not a substitute for a real deep clean. The NSF/ANSI 12 mark on the machine certifies that its design is cleanable; keeping it clean is on the schedule, not the badge.
How do you run the Manitowoc clean cycle?
- Empty all ice from the bin so nothing is contaminated during the clean.
- Start the clean cycle. On an Indigo NXT, tap the on-screen clean or wash function; on older button and toggle models, move the switch to Clean or Wash. The machine drains and prompts you to add cleaner.
- Add the diluted Manitowoc cleaner and let the cycle circulate it through the water system and over the evaporator. The solution will foam and darken as it lifts scale.
- Follow the machine’s rinse prompts. Do not cut the rinses short; leftover cleaner sours the first batches of ice.
What does the clean cycle miss?
The cycle does not reach everything. Remove the water curtain, the water distribution tube, and any removable food-zone parts, and scrub them with cleaner solution to clear scale and slime from the small orifices. Rinse them. Those small parts hold the scale and slime the cycle cannot reach, so they have to come out and get scrubbed by hand.
How do you sanitize and finish?
Run Manitowoc sanitizer through the sanitize cycle, then wipe the bin interior, the door, and every food-zone surface with sanitizer solution and let them air dry. Reinstall the parts and return the machine to ice making. Discard the first full batch of ice as a precaution.
Common questions
How do you clean a Manitowoc ice machine? Clean and sanitize it at least every six months, and more often on hard water or heavy use. Manitowoc also sets a lower limit: do not clean more often than once every two months, because the cleaner is corrosive. It is a two-step job: Manitowoc Ice Machine Cleaner to strip mineral scale, then Manitowoc Sanitizer to kill mold and slime. They are different chemicals and both are required.
How often should you clean a Manitowoc ice machine? At least every six months, and more often if the water is hard, the machine runs at high volume, or it sits in a hot back-of-house. Do not clean more often than once every two months: Manitowoc states that a shorter cleaning interval must be avoided, because the cleaner is corrosive. The USGS classifies water at 121 to 180 mg/L as calcium carbonate, roughly 7 to 10.5 grains per gallon, as hard. An Indigo NXT posts a cleaning reminder, but that only tracks elapsed time; it cannot tell whether the machine is actually clean.
Can you use a generic ice machine cleaner? Only if Manitowoc approves it. Manitowoc evaporators are nickel plated, and the manufacturer warns that a descaler or sanitizer of another brand can cause damage that is “not covered under the warranty.” Match Manitowoc’s cleaner and sanitizer, and never substitute bleach for the sanitizer step.
Does a water filter mean you can skip cleaning? No. A filter cuts the scale that hard water builds, which helps, but it does not kill biofilm and it does not change the cleaning interval. You still clean and sanitize on schedule.
A scaled, slimy machine makes less ice and works harder to make it, and the biofilm it grows is what fails a health inspection. ProToCall descales and sanitizes commercial ice machines on a schedule set to your water and your volume. Call 866-297-5082 or schedule Manitowoc ice machine repair and service. If yours has also stopped making ice, start with how to reset a Manitowoc ice machine.