Outdoor ice merchandiser freezer with an ICE sign on top

Generic photo: Athena Sandrini · Pexels License

Undercounter ice machine 'no ice' or bad cubes: check the water supply and drain against the maker's limits first

Ice machines are fussy about the supply: pressure, water temperature and drain fall all have published limits, and they differ by brand. U-Line's 15 in clear-ice machines want 20-120 psi cold water on a 1/4 in compression fitting and a gravity drain falling about 1/4 in per foot (or a pump model with up to 10 ft lift). Manitowoc's NEO undercounters want 20-80 psi and 45-90 °F water, with a 3/8 in FPT inlet and a 1/2 in FPT drain. Confirm the install meets those numbers before replacing valves, pumps or boards.

Single source ~30 min easyBrands: U-Line, Manitowoc, All

Before you start

Unplug the machine and shut the water off before opening fittings.
Connect only to potable cold water; follow the local plumbing code for backflow protection and the drain air gap.
Ice machine cleaner is acidic: gloves and eye protection when you clean as part of the diagnosis.

Diagnostic steps

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