# Scotsman Undercounter Ice Machines: Install, Use and Clean > How to install, start up, operate and clean Scotsman undercounter ice machines, using the maker's own clearance, temperature and cleaning figures. How-to by Norpex. Published 2026-10-15, updated 2026-10-15. Canonical: https://norpex.ca/guides/scotsman-undercounter-ice-machine-guide ![Stainless steel undercounter ice machine with a front control panel](https://norpex.ca/m/b1/87/b187b973ab324e090f4f79a88c51f6331aed89473327a4e9c3315470cee2da2d.jpg) Pictured: [Scotsman UC0918GAX-1 18″ Air-Cooled Undercounter Self-Contained Ice Machine with Storage – 95 Lbs.](https://norpex.ca/product/scotsman-uc0918gax-1-18-air-cooled-undercounter-self-contained-ice-machine-with-storage-95-lbs) Scotsman's undercounter cube, nugget and flake machines install under a counter with front airflow, a water line, a gravity drain and a dedicated 115 volt circuit. This guide collects the maker's figures for clearances, start-up, daily operation, cleaning and service. ## Key takeaways - Scotsman undercounter machines come in cube (CU), nugget (UN), flake (UF) and UC Prodigy series, in air-cooled and water-cooled versions. - The manuals require air between 50 and 100 degrees F, water between 40 and 100 degrees F, and a drain falling at least 1/4 inch per foot. - The manuals here describe 115 volt, cord-connected units with a 5-15P plug on a dedicated circuit. - Scotsman calls for water system cleaning about twice a year with Clear 1 scale remover followed by a sanitizer. - On R290 models, repairs must be done by a technician certified for R290 using Scotsman factory service parts. ## The Scotsman undercounter range Scotsman sorts its undercounter machines by ice type. The CU series makes cubes in small, medium, large and gourmet sizes, the UN series makes nugget ice, the UF series makes flake ice, and the UC Prodigy models are self-contained cube machines with built-in storage. Named capacities run from 58 lbs on the CU0415MA-1 up to 440 lbs on the UF424A-1 flaker, with the AFE424 at 395 lbs. Most models are air cooled; water-cooled versions include the UC2024SW-1, UC2724MW-1, UF424W-1 and CU3030SWX-1. The manuals covered here are for 115 volt models; check the spec sheet for any other voltage. Several models, including the X-series nugget and flake units, use flammable R290 refrigerant. ## Where to install it Every manual describes an indoor machine for a controlled environment. The installation and user manual for the CU0415, CU0715 and CU0920 and the UN and UF manuals set air limits at 50 to 100 degrees F and water between 40 and 100 degrees F; the UC2024 and UC2724 manual lists the same air range and a 40 degrees F water minimum. Airflow moves in and out the front, so the unit can be built into a cabinet. The CU, UN and UF manuals suggest 1/8 inch (3 mm) of side clearance, 1/4 inch (7 mm) on top and 4 inches (100 mm) at the back for utilities; the UC2024 and UC2724 manual allows 0 clearance at the back. Never block the front louvers, and leave room to remove panels for service. ## Water, drain and electrical setup The CU, UN and UF models connect through a 5 foot (1.5 m) 1/4 inch OD plastic tube at the back, with a hand shut-off valve within sight; the UC2024 and UC2724 manual specifies a 3/8 inch FPT inlet and a filtered supply. The UN and UF manuals require a conductivity of at least 10 microSiemens/cm, so ultra-pure water will not work. Each machine needs a gravity drain: a 3/4 inch FPT fitting, rigid tubing to local code, a fall of at least 1/4 inch per foot (20 mm per metre), an 8 inch (200 mm) vertical vent tube at the machine and venting on horizontal runs of 5 feet or more. These are cord-connected 115 volt units with a 5-15P plug on a dedicated circuit; the UC2024 and UC2724 manual allows a 15 A maximum fuse or HACR breaker and 104 to 126 VAC. The Scotsman Undercounter Units - Easy Install video notes that the power cord, plug and adjustable legs come included. A qualified, licensed installer must make the water and electrical connections to local code. ## Start-up For the CU0415, CU0715 and CU0920, the manual's start-up is to remove the front panel, turn the water on first, then move the On/Off/Wash master switch to On. The reservoir fills, and after 2 minutes the pump and fan start under a blue freeze light. Cycles run 28-30 minutes for the CU0415, 16-18 for the CU0715 and 14-16 for the CU0920 at 70/50 degrees F, and a warm bin fills in about 10-12 hours. The ice bridge is factory set at about 1/8 inch (3 to 4 mm). On the UN and UF models, confirm the Power light is on and the Water light is off, then push and release the On button; a blinking red Water light means the reservoir has not filled. The UC2024 and UC2724 start when the On/Wash/Off rocker moves to On; after a 90 second delay, water flows into the sump and the unit begins its cycle. Their manual gives the cycle times for each model. ## Daily use and the controls Lift the door by its bottom edge and slide it up, scoop the ice, and close the door. The bin is insulated but not refrigerated, so some melt is normal. Keep the front vents clear and never stand on the cabinet. The cube models run from a three-position master switch, with a Freeze Mode light on during the freeze cycle and a Timer On light at the trigger temperature. Harvest time adjusts with the plus and minus buttons across 10 settings, and the ice bridge comes preset from the factory. The machine stops when ice touches the bin's metal tube and restarts when ice is removed. The nugget and flake models have On and Off buttons behind the louvered panel: a green Status light while making ice or when the bin is full, a Clean light after 6 months of power-up time, and a Water light that shuts the unit down until water returns. On the UC2024 and UC2724, an ice sensing plate stops the machine when ice piles onto it; the manual's tip is to scoop ice to the sides and front. The Scotsman Undercounter Cube - Simple to Operate video points to each unit's QR code, which pulls up its model number, serial number, user manuals, cleaning instructions and parts list. ## Cleaning and sanitizing The manuals call for water system cleaning about twice a year, more often with heavy use or mineralized water. Our how to clean a commercial ice machine guide covers the general method; the figures here are the Scotsman-specific ones from the maker's manuals. The CU0415, CU0715 and CU0920 manual mixes 5 oz of Scotsman Clear 1 into 2.5 quarts (2.4 L) of 95 to 115 degree F water for a 10 minute Wash, then sanitizes with 1.6 oz of nu-Calgon IMS in 1 gallon of water. The UN and UF manuals use 2.5 oz of Clear 1 per quart of 90 to 110 degree F water, started by holding the On and Off buttons for 5 seconds; the auger runs 20 minutes, ice resumes in 5 to 8 minutes and the cycle ends after 40 minutes. Sanitizing uses 4 oz (118 ml) of NuCalgon IMS in 2.5 gal (9.5 L) of water for 200 ppm, run at least 15 minutes. The UC2024 and UC2724 manual has its own cleaning sequence with Clear 1 scale remover and a sanitizer; follow it step by step for those models. Its air filter slides out of the lower front grill for washing, and the condenser fins need semi-annual brushing and vacuuming with the unit unplugged. Scaled optical sensors on the nugget and flake models cause a false bin-full signal; the manuals clean the lens with a cotton swab and 4 oz of Clear 1 in 1.5 qt (1.4 L) of water, never a sharp object. ## Service and troubleshooting Before service, the manuals point to the water supply, power supply or room temperature when there is no ice; a dirty condenser, hot room or blocked airflow when production slows; and restricted spray jets when cubes form poorly. On the nugget and flake models, a green Status light with no ice being made means scaled sensors, and all four indicator lights blinking means call for service. The R290 manual requires a Scotsman recommended technician certified for R290 equipment and Scotsman factory service parts; for any repair, contact the manufacturer's authorized service network. For questions about a model, ask Norpex. ## Videos from the maker - [Scotsman Undercounter Units - Easy Install](https://www.youtube.com/watch?v=fMEofc72ReI) (Scotsman) - [Scotsman Undercounter Cube - Simple to Operate](https://www.youtube.com/watch?v=F-QY2GagJd4) (Scotsman) ## Common questions ### Can a Scotsman undercounter machine be built into a counter? Yes. Airflow is in and out the front, so the manuals allow built-in installation with the front unblocked, about 1/8 inch at the sides, 1/4 inch on top and 4 inches at the back, or 0 back clearance on the UC2024 and UC2724. ### What room and water conditions do these machines need? The manuals call for indoor air between 50 and 100 degrees F and water between 40 and 100 degrees F. Pressure limits run from 15 to 80 psi on the CU, UN and UF models and 20 to 80 psi potable on the UC2024 and UC2724. ### How often should the machine be cleaned? About twice a year, more often with heavy use or mineralized water. On the nugget and flake models, a Clean light comes on after 6 months of power-up time between cleanings. ### Do water-cooled models need extra plumbing? Yes. The UC2024 and UC2724 manual adds a 3/8 inch FPT condenser inlet that must not be filtered, a 1/2 inch FPT condenser drain, and a water regulating valve factory set to 135 PSIG, with condenser inlet pressure between 20 and 145 psi. ## Related guides - [Commercial Ice Machine Buying Guide: Cube Types, Cooling and Sizing](https://norpex.ca/guides/ice-machine-buying-guide) - [How to Clean and Sanitize a Commercial Ice Machine](https://norpex.ca/guides/how-to-clean-a-commercial-ice-machine) ## Shop the catalogue - [Ice Machines](https://norpex.ca/products/ice-machines-ice-and-ice-cream) - [Ice Machine Bins](https://norpex.ca/products/ice-machine-bins) - [Water Filtration Systems](https://norpex.ca/products/water-filtration-systems)