Restaurant Ice Machine Water Filtration in Phoenix

An ice machine freezes water, and the minerals do not freeze with it. Scotsman's manual explains that purer water freezes first, which concentrates impurities in the reservoir where they form hard deposits called scale. The machine flushes some of that away each cycle, but some sticks to parts, causes malformed cubes and, in the maker's words, can eventually shorten machine life.

Phoenix water makes that worse. The city's 2025 report lists hardness of 10 to 17.6 grains per gallon. That is a lot of calcium and magnesium for a machine to handle all day, every day. The result is cloudy or soft cubes, a mineral film in the bin and a cleaning cycle that comes up short.

We plumb the water side. That means the supply line and its shutoff valve, a pressure check, and an indirect drain that ends in an air gap above a floor sink. If the machine's water line is leaking or the drain is backing up, we fix the plumbing. We also jet the soda and ice-well drains with a cleaning solution when they smell, and we install 5-stage reverse osmosis systems.

We do not service the ice machine or its filter cartridges. Cleaning cycles, evaporators, compressors, sensors, filter changes and descaling the machine itself belong to your equipment service company. Hoshizaki's manual even notes that the water line installation is not covered by its warranty, which is one reason the plumbing needs to be done right.

A sediment and carbon filter takes out particles, chlorine taste and odor. Scotsman says filtering is generally a good idea and that the right filter can remove taste and odors as well as particles. It does not remove the dissolved minerals that cause scale. For that, Scotsman's manual names reverse osmosis and polyphosphate feeders as treatment methods, and both come with the maker's rules. Scotsman says an RO system for an ice machine should include post-treatment, and that deionized water is not recommended.

Which cartridge fits depends on the machine, and the maker usually names one, because a wrong cartridge can starve the machine of flow. Your equipment service company handles that choice and the changes. Our part is making sure the supply line, shutoff and pressure feeding it are right. If you are weighing RO, tell us the model so we can check the maker's post-treatment rule before anything is installed. For the upkeep side, see commercial kitchen filter changes.

Softeners are the usual Phoenix answer to hard water, and they are a poor fit for ice. A softener swaps calcium and magnesium for sodium, and Scotsman says it does not recommend softeners for ice machines because very hard water that has been softened can give white, mushy cubes that stick together. Hoshizaki, by contrast, says softeners may be required depending on water quality. The two makers disagree, which means the manual for your model decides.

If the kitchen already has a softener, check the machine's manual before the ice machine's supply line is tied in downstream of it. The manual for your model is the tiebreaker.

Maricopa County requires an indirect waste line, with a minimum 1-inch air gap above the flood level of a floor sink, no more than 10 feet of run, and a vented trap at the receptor. Hoshizaki's manual calls for at least 2 vertical inches of air gap, so the larger number wins on that machine. Watch for a drain hose shoved down into the floor sink, a drain tied directly into a trap, or a bin drain that has slowed down. See how to drain a commercial ice machine legally.

On the supply side, the county's guide says equipment on a water supply needs backflow protection or an air gap and that ice machines are typically exempt. Soda systems are not exempt. Soda and ice machine backflow explains the difference. Hoshizaki adds that water hammer has to be resolved by a qualified plumber before installing the icemaker, and that is a plumbing job.

If your cubes are cloudy only on one machine and the neighbor's are clear, the issue may be the machine's cleaning cycle, not the water. If the problem is a bin that will not drain, a filter will not help. If the machine's water supply pressure is outside the manual's range, 10 to 113 PSIG for the Hoshizaki model and a minimum of 20 PSIG flowing for the Scotsman, we fix the pressure first. And if your machine is water-cooled, its condenser water is a separate plumbing question, covered in air-cooled versus water-cooled ice machines.

Tell us the make and model of each machine, the city and whether the drain goes to a floor sink. We offer free estimates and an upfront price before work starts. See restaurant plumbing and our commercial reverse osmosis installation page if you also want RO drinking water.