Answers · Undercounter ice machines
How Do I Clean a Sub-Zero Undercounter Ice Machine?
The short answer
Every six months, run the machine's cleaning cycle twice, first with the descaler made for your model and then with its sanitizer, and use nothing else, bleach included.
Check in this order
- Touch CLEAN to start a two-minute harvest, then empty the bin of cubes.
- When the CLEAN light flashes, about three minutes later, lift the water shutters and pour 4 ounces of undiluted descaler into the spray area.
- Let the ten-minute clean and eight rinses run, about half an hour, until the light goes out.
- Touch CLEAN again and, at the flash, pour one tablespoon of undiluted sanitizer into the same spot for another half hour.
- Rinse the bin with hot water to melt any ice made during the cycles.
Past this line it is a technician's job Sub-Zero Repair Tacoma, (206) 472-1140
Behind the answer
Those steps follow the UC-15I guide. The Designer model takes the same descaler and sanitizer but has its own cleaning drawer and floor light, so follow its guide; the 315I needs a different scale remover, and the wrong product can cause damage.
Even on Tacoma Water, softer than hard water by the utility’s own account, the six-month interval stands whatever the filtration. Shallow, white or cloudy ice after two good cycles means a machine dirty enough to need taking apart, not an owner job.
Related questions
Can I use vinegar or bleach instead?
Sub-Zero does not recommend any cleaner or sanitizer but its own, bleach included, and the UC-15I guide warns against vinegar and alcohol-based cleaners on interior surfaces. If two proper cycles still leave the ice poor, call Sub-Zero Repair Tacoma on (206) 472-1140.
Where do the descaler and sanitizer come from?
From Sub-Zero's online store or a Sub-Zero parts distributor. What was once sold as cleaner is now called descaler, and Sub-Zero says the solution has not changed. Neither product has a shelf life, so a spare pair keeps until the next clean.
- Signed
- Marta Fennimore
- Role
- Refrigeration technician — ice systems and water supply
- In the trade
- 12 years
- Holds
- EPA 608 certified
- Checked
- Sep 18, 2026