Error i30 on AEG dishwasher: causes, diagnosis, and solution

What the i30 error means on AEG dishwashers

The i30 error indicates that the dishwasher’s leak-protection system has detected water where it shouldn’t be, usually in the base, lower tray or a dedicated leak-protection area. On many AEG models this is an anti-overflow alarm that stops the cycle and in many cases triggers automatic draining to prevent flooding or electrical damage. This is a safety response, not a cosmetic panel fault, and should not be ignored.

What the appliance is actually monitoring

The machine monitors moisture or water accumulation in a critical part of the chassis using a float or sensor. When the sensor detects water, the appliance interprets it as a potential flood and locks out operation. Sometimes the unit will keep pumping to evacuate the detected water — this is intentional and part of the protection protocol. While the base remains wet or the sensor reads moisture, the appliance will not return to normal on its own.

Common causes

Internal leaks

Small but persistent leaks are the most frequent trigger. They can originate from hoses, clamps, loose connections, the pump, the tub, or worn door seals. Over time seals lose elasticity and clamps can work loose; repeated small drips during cycles are enough for water to reach the base and activate the protection.

Excess foam

Using the wrong detergent, too high a dose, or residual detergent build-up can produce excessive foam that behaves like an overflow. Foam can migrate into areas where the sensor interprets a leak, producing a false-positive i30 activation.

Incorrect loading and spray arm obstruction

Pots, trays or tall items can block spray arms or deflect jets toward the door or chassis edges. Repeated jets onto the same point can stress seals and cause dripping. Spray arms that are dirty, obstructed or hitting dishes distribute water unevenly and may contribute to the problem.

Installation and leveling

In built-in or integrated units, slight tilt or poor seating can encourage water to flow to the base area. A few millimetres can change water paths and concentrate moisture where the protection system detects it.

Code variants and what they mean

• i30 — Leak protection / anti-overflow activated: water in the base, internal leak, excess foam, or diverted spray. The dishwasher stops and may pump continuously.
• 30 / .30 — Visual or abbreviated variants of the same warning shown on some panels. Diagnosis and checks are identical.
• C3 — Alternate model-specific signal for water protection activation. The technical meaning is equivalent: check for water accumulation and leaks.

Symptoms and typical behaviour

The most common symptom is an interrupted wash cycle accompanied by the i30 (or variant) warning. You may also notice continuous or repeated draining. In some cases the error clears after the appliance has been switched off for hours and the base has dried; this is a temporary reprieve, not a fix. If the root cause remains, the warning will reappear on the next cycle.

Immediate safety steps

1. Turn off the water supply to the dishwasher.
2. Unplug the unit from the mains (or switch off the breaker) to avoid electrical risk while moisture is present.
3. Leave the door slightly open and allow the base to dry for several hours; this can confirm whether the sensor responds to residual moisture or recurring leaks.

What to inspect before calling a technician

Work through these checks in order — they are low-cost and often reveal the cause:

• Surroundings: inspect the floor under the appliance, the plinth, door area and rear for damp marks, drips or recent moisture smells.
• Filters and debris: clean bottom filters and check for food debris that can alter water flow.
• Spray arms: remove and clean spray arms; ensure they spin freely and do not hit crockery.
• Loading: re-arrange to prevent items from blocking arms or deflecting jets.
• Detergent: use dishwasher-specific detergent in the correct quantity to avoid foam.
• Hoses and clamps: inspect inlet and drain hoses and visible clamps for leaks or looseness.
• Door gasket and seals: check for wear, hardening or debris that could allow slow leaks.
• Leveling and installation: verify the appliance is level and correctly seated.

Why the error may clear temporarily

When the base dries, the float or sensor stops detecting moisture and the appliance may allow a cycle to start again. This is a temporary state: if the underlying leak, foam issue, or misdirected spray remains, the error will recur. Treat the temporary restart as a diagnostic sign, not a repair.

When to call a technician

If the base remains wet after drying attempts, the i30 returns repeatedly, or you cannot locate any visible cause, arrange an authorized service visit. A technician can locate hidden leaks, test clamps, pumps and sensors, and determine whether the detection system itself or an internal component is at fault. Handling electrical components near retained water without a clear plan can worsen the problem.

Quick troubleshooting checklist

1. Switch off water and power immediately.
2. Open the door and let the unit dry for several hours.
3. Inspect floor, plinth and back for external signs of leakage.
4. Clean filters and spray arms; check spray-arm rotation.
5. Re-load dishes to avoid obstructing spray arms; reduce detergent dose.
6. Check hoses, clamps and visible seals for leaks.
7. If error persists, contact an authorized technician.

Final recommendations

Do not ignore the i30 warning. It is a preventive safety feature designed to avoid floods and electrical damage. Use the temporary clearing of the error as a cue to inspect thoroughly — continued use without diagnosing the cause risks further damage. If you prefer guided help, use the free error code finder provided on the site to identify model-specific guidance and repair options.