Washing Machines on RO/ SpotZero Water

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Onboard washers and washer-dryers run fine on watermaker (RO) water, but need reduced detergent and correct hardness settings. This article covers Ocean Alexander yachts where the domestic system is fed by a watermaker or shore water passed through RO.

Applies to: crew and owner laundry machines, front-load and stacked units
Audience: Ocean Alexander owners, captains, crew and authorized service providers
Out of scope: dishwashers (same water principles apply; separate article)

Background: RO / zero-TDS water #

RO water has near-zero dissolved minerals (TDS close to 0 ppm, hardness close to 0 °dH), so it behaves like extremely soft water in a washer.

No calcium or magnesium to tie up detergent surfactants, so the same dose produces far more foam. LG notes soft water causes detergent to over-suds and calls for a reduced dose even with HE detergent (LG).
Less detergent needed. Detergent demand rises sharply with hardness, so on RO water the dose can be cut substantially (EP0578006).
No scale. Heating elements and valves stay clean; descaling is rarely needed.
Slightly aggressive. Demineralized water tends to be mildly acidic and pulls ions from metals. Expect more wear on copper, brass fittings and seals over time; this is general water-chemistry guidance, not a manufacturer finding.

Known issues on RO water #

Nearly every RO-related washer complaint traces back to too much detergent.

Issue	What crew sees	Root cause
Oversudsing	Foam in drawer or door, long cycles, extra rinses, “suds” error codes	Full detergent dose in zero-hardness water
Unbalanced / no spin	Load stays wet, spin aborts	Machine’s suds detection blocks spin to protect the pump
Residue and odor	Stiff towels, slimy gasket, musty smell	Unrinsed detergent and softener building up in drum and hoses
Leak at door or drawer	Water on deck under the unit	Foam pushed out of the dispenser vent or door seal
Drain pump faults	Pump error, slow drain	Foam air-locking the drain pump
Fitting corrosion	Green or white crust on brass inlet fittings	Long-term exposure to demineralized water

Required settings and detergent #

Set the machine to its softest water setting and start detergent at one-quarter to one-third of the label dose.

Water hardness setting: set to the lowest / “soft” level if the model has one (see Maytag and ASKO below). This shortens dosing on auto-dose models.
Auto-dose (bulk dispensers): set dose to minimum or switch to manual dosing.
Detergent: HE, low-suds only. Liquid preferred. Start at 1/4–1/3 of the label dose; increase only if cleaning is poor.
Pods: avoid. Fixed dose cannot be reduced and is the most common cause of foam calls.
Fabric softener: use sparingly or not at all; RO water already leaves fabric soft.
Maintenance cycle: run a hot drum-clean cycle monthly with no load and no detergent.
Crew briefing: add the reduced-dose rule to the laundry placard and the vessel handover notes.

Maytag and ASKO units #

Both brands foam heavily on RO water at label doses; the fix is the same, but the symptoms and settings differ.

Maytag

Maytag states that very soft water may need less detergent, and that excess suds slow the spin, leave loads very wet and can trigger error codes (Maytag).
Sud / Sd on the display (front-load): the washer has detected excess foam and extends the rinse, pausing to let suds break. Let it finish; then run a Clean Washer cycle (Maytag).
F0 E2 on many Whirlpool-platform Maytag models is also an over-suds code; treat it the same way.
Check the detergent concentration: HE detergents run 2x, 4x and 8x, so an 8x product needs about a quarter of a 2x dose. On RO water, start below even that.
Avoid “no splash” or thickened chlorine bleach; Maytag notes its thickener adds suds.
Run Clean Washer monthly with affresh or liquid chlorine bleach.

ASKO

ASKO washer manuals set the detergent amount by water hardness and include a dosing table by hardness level (e.g. W6863, W6903). On RO water, use the softest-water figure, then reduce further if foam persists.
If the model’s settings menu has a water hardness option, set it to the lowest level.
ASKO units are often built in on yachts; foam escaping the dispenser can run behind cabinetry. Check the base and door seal after any foam event.
After a foam event, run a rinse-only cycle with no detergent before the next load.

Open item: confirm Maytag and ASKO model numbers fitted by hull so this section can list exact menus and codes.

Inlet screen and water supply checks #

Clean the inlet screens at each annual service.

Inlet screens: remove with needle-nose pliers, rinse, reinstall. Debris after watermaker or tank work is common.
Supply pressure: most domestic washers need roughly 1–10 bar (15–145 psi) at the inlet. Confirm the domestic pump and accumulator hold pressure through the fill; low pressure causes slow-fill and “no water” errors.
Hot supply: if the unit is cold-fill only, cap or do not connect hot.
Shutoffs: valves should be reachable without pulling the unit. Close them when the vessel is left unattended.

Troubleshooting #

Symptom	Likely cause	Action
Foam out of drawer or door	Over-dosing on RO water, pods	Cut dose to 1/4–1/3; stop pods; run rinse-only cycle
Load wet, spin skipped	Suds lock-out	Rinse cycle, then reduce dose
Musty smell, slime on gasket	Detergent/softener residue	Hot drum-clean cycle; clean gasket and drawer; reduce dose
Slow fill / no-water error	Clogged inlet screen, low pump pressure, kinked hose	Clean screens; check domestic pressure; reroute hose
Water under unit	Hose or fitting leak, foam overflow	Check hose ends and washers; check AquaStop trip; see oversudsing
Leak protection tripped	Leak detected at base or hose	Find leak before reset; replace safety hose if it was the source
Crust on inlet fittings	Corrosion at brass	Replace fitting and hose

Warranty notes and escalation #

Oversudsing, residue and odor from detergent misuse are operational, not warranty defects.

Not covered: suds-related faults, residue/odor, hoses damaged by routing or chafe.
Possibly covered: pump, control board or valve failure with correct dosing confirmed; factory hose or fitting failure inside the warranty period.
Before filing: photograph detergent in use, dose setting, hose condition, and any error codes.
Escalate to the appliance OEM for board, motor or leak-protection failures; submit through Ocean Alexander Yacht Service with the hull number.

Sources #

Need Assistance?

For technical support, warranty assistance, parts, or to schedule service:

Ocean Alexander Yacht Service
East Coast Yacht Group
2955 W State Road 84 Fort Lauderdale FL, 33312
954-530-2033

oayachtservice.com

This article is part of the Ocean Alexander Yacht Service Knowledge Base. Information is provided for general guidance and should not replace the applicable Owner’s Manual or service procedures.

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