What this error means
Anti-flood warning — the dishwasher has detected water in the base tray and has locked out to prevent flooding.
The i30 error on a Zanussi dishwasher means the anti-flood float switch located in the base tray of the machine has been triggered. Zanussi dishwashers have a shallow plastic base tray that collects any water escaping from internal leaks. A float switch sits in this tray and activates i30 the moment water is detected. This is a safety-critical protective feature designed to prevent kitchen flooding. The most common causes are excessive foam from too much or the wrong type of detergent, a leaking or perished door seal, a loose or cracked internal hose connection, a leaking pump seal, or a cracked outer tub. The machine will lock out completely until the water in the base tray is physically removed.
Step-by-step
Symptoms to look for
- i30 displayed during or immediately after the start of a programme
- Dishwasher locks out completely and will not begin or resume any programme
- Water visible on the kitchen floor beneath or in front of the dishwasher
- Smell of damp, mildew, or detergent from beneath or around the machine
Diagnostic steps
Disconnect the dishwasher from the mains power socket immediately. Water in the machine base is in close proximity to the motor, pump, wiring harness, and control board electronics. Investigating or attempting to operate the machine while powered is a serious electrocution risk.
With the machine fully unplugged and the water supply tap turned off at the wall, open the under-sink cabinet and pull the dishwasher forward enough to access its sides. With a second person assisting, tilt it carefully backwards at approximately 45 degrees and hold this position for 30 to 60 seconds. Water in the base tray will run toward the rear ventilation openings and out onto the floor. Place towels behind the machine beforehand.
After draining by tilting, stand the machine upright and remove the lower front kickplate panel to allow air to circulate into the base tray area. If possible, direct a hair dryer on a cool, low setting into the base for several minutes to speed drying. The float switch must be completely dry before i30 will clear and normal operation resumes.
Excessive foam produced by using too much detergent, using non-dishwasher detergent, or using the wrong tablet format overflows during the wash cycle and drips into the base tray through internal gaps. This is the single most common cause of i30 in otherwise fully functional machines. Confirm you are using the correct Zanussi-compatible dishwasher detergent in the correct quantity for your local water hardness setting.
Once the base is confirmed dry and i30 has cleared, restore power and water and run a Quick Wash programme. Remain present and observe the machine throughout the full cycle. Watch carefully around the door seal perimeter during the wash phase, beneath the machine at kickplate level during the drain phase, and around the soap dispenser area during filling.
With the machine unplugged and tilted or on its back, remove the base cover panel to view the float switch assembly. The float arm should be in the lowered, resting position with the tray completely dry. Confirm the float arm moves freely up and down with no debris or wiring holding it in the raised (triggered) position.
When to call an engineer
- Door seal is visibly split, perished, torn, or has holes — must be replaced before the machine is used again
- Pump seal is confirmed leaking — water marks or residue visible around the pump body under the machine
- Outer tub or base tray has a visible crack or fracture — requires specialist assessment and repair
- i30 persists with the base tray completely dry — float switch has failed in the triggered position and must be replaced
Frequently asked questions
Is i30 dangerous?
Can using too much detergent cause i30 on a Zanussi dishwasher?
How do I reset i30 after drying the base?
Why does i30 keep coming back on my Zanussi dishwasher?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Door Seal | £15 - £30 | 🛒 Amazon UK → |
| Door Seal | £10 - £20 | 🏷️ eBay UK → |
| Float switch | £20 - £30 | 🛒 Amazon UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.