AEG dishwasher i20 error
Stop using the machine
The machine has tried to empty itself and the water has not gone, so it has stopped with dirty water still standing in the base. The filters in the base of the tub are clogged with food waste and grease, so the pump cannot draw water through them is the most common cause.
- Difficulty
- DIY
- Time needed
- About 30 min
- Checks
- 6 steps
The same fault is shown as C2, F2, AL6 on some AEG series, depending on the display and the model year.
Before you start
- Switch the appliance off and unplug it before reaching into the base. Broken glass collects there and the pump is driven by a mains motor.
- Treat the standing water as contaminated. Wear gloves and wash your hands afterwards.
What it means
The machine has tried to empty itself and the water has not gone, so it has stopped with dirty water still standing in the base.
Most likely causes
Ordered from most to least common, with what each one looks like:
| Cause | How likely | What you would see |
|---|---|---|
| The filters in the base of the tub are clogged with food waste and grease, so the pump cannot draw water through them | high | Lifting the filter out shows a mat of debris and the standing water smells stale |
| The drain hose is kinked, crushed behind the machine, or looped higher than the pump can lift water | high | The machine was moved recently, or the hose rises well above the top of the appliance |
| The sink waste or trap the machine drains into is blocked, so there is nowhere for the water to go | medium | The kitchen sink beside the machine also drains slowly or gurgles |
| On a new installation the spigot on the waste pipe still has its sealing plug fitted | medium | The machine has never drained properly since the day it was fitted |
Fix steps
Tools needed
- Shallow jug
- Sponge
- Washing-up brush
-
Switch the appliance off and pull the plug out of the socket before putting your hands into the base of the tub.
Expected result The display is dark and the pump cannot run while you are working inside the machine.
-
Scoop the standing water out with a jug and finish with a sponge until the base is dry enough to see into.
Expected result The filter assembly is visible and no longer submerged.
-
Lift out the flat filter and twist out the cylindrical one, wash both under a hot tap with a brush, and clear the recess they sit in.
Expected result Water runs straight through both filters and the recess is clear of debris.
-
Follow the drain hose along its whole length, straightening kinks and checking it is not crushed where the machine sits back against the wall.
Expected result The hose runs in smooth curves with no flattened sections. If it does not, go to step 5.
-
Fill the kitchen sink and let it empty to prove the shared waste pipe is clear, clearing the trap if it drains slowly.
Expected result The sink empties briskly without backing up or gurgling. If it does not, go to step 6.
-
Refit the filters, making sure the cylindrical one is turned until it locks rather than sitting loose, then plug the machine back in and run a rinse programme.
Expected result You hear the pump working evenly, the base clears, and the fault does not reappear.
Parts needed
| Part | Part number | Typical cost |
|---|---|---|
| Drain hose | Varies by model | Varies by supplier |
| Filter set | Varies by model | Varies by supplier |
When to call a technician
Call a qualified technician if you work through every step above and the code comes back, if you find water where it should not be, or if any part of the job needs the machine powered up with panels removed. A repeat fault after a correct repair usually points at the control board rather than the part you replaced.
Common questions
What does i20 mean on a AEG dishwasher?
The machine has tried to empty itself and the water has not gone, so it has stopped with dirty water still standing in the base. The filters in the base of the tub are clogged with food waste and grease, so the pump cannot draw water through them is the most common reason for it.
Can I keep using the dishwasher?
No. Stop using the machine until the fault is resolved, because running it in this state risks further damage or a water leak.
Is this something I can fix myself?
Yes, for most people. The checks below need shallow jug, sponge and washing-up brush and take about 30 minutes.
Models this applies to
Related codes on the same machines
- i10 The machine asked for water and not enough arrived, so it stopped rather than starting a wash with an empty tub.
- i23 The cover that seals the drain pump is loose, fitted incorrectly, or missing altogether, so the pump cannot build suction and the water stays where it is.
- i24 Something solid has reached the drain pump and is stopping the impeller turning.
- i30 The anti-flood device in the base of the machine has been triggered by water where there should not be any.
- i40 The appliance cannot get a trustworthy reading of how much water is inside it, so it halts rather than guessing and either running dry or overfilling.
- i50 The motor that drives water up to the spray arms is not behaving as the control board expects, so the wash is abandoned.
Sources
- Electrolux Group (AEG), AEG support, dishwasher error code i20 / C2 / F2 / AL6, not draining (link) — retrieved 2026-07-26