Ice Makers and Drinking-Water Dispensers on Boats: Cleaning, Filters and Winterizing

Ice and dispensed water are only as clean as your tank. If the tank water tastes or smells off, clean and sanitize the freshwater system first (see the water tank cleaning guide). BoatUS notes that a good drinking-water filter greatly improves taste and removes many impurities, and that an ultraviolet (UV) unit can kill viruses.

With a multimeter, confirm the outlet or supply has the right voltage when the unit runs. An ice maker draws a lot of power for many hours, which can quickly drain batteries through an inverter. Check the nameplate wattage and plan to run it on shore power or the generator, or only briefly on the inverter. Dometic notes that long cable runs, shared circuits and corroded connections cause voltage drop that makes refrigeration work harder; the same applies to ice makers.

• Dump the ice bin every few days when you're using it, so water keeps moving (BoatUS advice). Old ice picks up odors.
• Discard the first batch after start-up, cleaning or a filter change.
• Keep the scoop out of the bin, and wash it regularly.
• Leave the unit off and the door open if you won't use it for a few days or more, to stop odor and mold.

Most makers suggest replacing filters about once a year, or sooner if flow drops, cubes get small or hollow, or the taste changes; check your filter's label. Shut off the water supply and relieve pressure, put a towel under the housing, then swap the cartridge as its instructions say. Inspect the housing O-ring and seat it correctly; most housings are hand-tightened only. Flush water through the new filter as directed, and write the date on the housing.

With the power off, empty the bin and let any ice melt. Wash the bin, scoop and interior surfaces with mild soap and warm water, rinse, then sanitize with the product the manual recommends, and rinse again if the label says to. U-Line advises against putting parts in a dishwasher unless the manual allows it, and against harsh or abrasive cleaners on the interior.

Minerals in the water leave scale on the evaporator (the cold plate or fingers where ice forms), the water pump and the valves. U-Line's clear-ice and nugget machines have a cleaning reminder; others just make less ice or cloudy cubes. Run the maker's cleaning cycle with the ice machine cleaner it approves, follow every step, and throw away the ice from the first harvest afterward (U-Line says the first harvest for clear-ice units, and the first 10 minutes of ice for nugget units). Using the approved cleaner also protects your warranty. Don't touch the evaporator while the machine is running.

Like a fridge, an ice maker dumps heat through a condenser, usually behind a front grille. Dometic notes that when heat is trapped in tight cabinetry, cooling drops and components wear faster. With the power off, vacuum or brush dust and lint from the condenser grille every few months, and make sure nothing is stowed against the vents.

If your unit has a drain line, pour a little clean water into the bin and make sure it drains away freely. A slow drain causes overflowing water, puddles and musty smells. Clean the drain fitting, make sure the hose has a steady downhill run with no sags, and check any drain pump and its float. Find where the drain ends (sump, gray tank or through-hull) and confirm it's clear.

• Run the faucet for a minute after the boat has sat idle to flush stagnant water from the line.
• Change its filter on the maker's schedule, the same way as in step 4.
• Clean the spout and aerator; scale and slime collect there.
• For bottled-water dispensers, clean and sanitize the reservoir and spigots when you change bottles, following the dispenser's instructions.

Work from simplest to hardest:

• No ice at all: Is the unit on and the bin-full arm or sensor free? Is the freshwater pump on and the tank not empty? Is the supply valve open? A clogged filter or frozen fill line also stops it.
• Small, hollow or few cubes: low water flow (old filter, low pump pressure, kinked line), scale, or a hot cabin and blocked condenser.
• Cloudy, smelly or bad-tasting ice: stale water in the line, an old filter, a dirty bin or tank water that needs treating. Clean and sanitize, change the filter, dump the bin.
• Water on the floor: a blocked drain, loose fill fitting, or a cracked line (often after a freeze).
• Breaker trips or unit won't power up: stop and have a marine electrician check it.

Freezing water cracks lines, valves and filter housings. BoatUS warns that ice can crack plastic fittings, pumps and valves in water systems, and that many insurance policies exclude freeze damage unless you buy that coverage.

1. Turn off the ice maker and its breaker, empty the bin, and clean and dry it.
2. Close the ice maker's water supply valve.
3. Drain the line as the manual says. On many units this means disconnecting the line at the fill (solenoid) valve and letting it drain, and some makers allow blowing it out with low-pressure air. Drain the unit's internal reservoir or pump if it has one.
4. Remove filter cartridges and leave the housings empty and drained, or bypass them, before antifreeze goes through the boat's plumbing.
5. Only run pink propylene glycol antifreeze into the ice maker if its maker allows it. Otherwise keep the ice maker's supply valve closed while the rest of the freshwater system is winterized.
6. Leave the door propped open so it dries.

Flush the freshwater system until all antifreeze is gone and the water tastes clean. Fit new filters, reconnect the ice maker's line, open the valve and check every fitting for drips. Turn the unit on, sanitize if the manual calls for it, and discard the first batches of ice.