Dishwasher not draining or not filling: what to check

Why these two codes are worth your evening

Of the seventy-odd dishwasher codes on this site, the ones that appear most are the two that say water did not move: it did not leave in the time allowed, or it did not arrive. Bosch E24, Hotpoint F03, AEG i20, LG OE, Samsung 5C and Miele F11 are the drain family. Bosch E15 is not one of them, and the distinction matters enough to get out of the way first: E15 and its relatives mean water has reached the base of the machine, and they carry the opposite instruction — isolate, do not investigate. If your code is in the leak and flood family, stop here.

For the drain and fill codes, every manufacturer publishes something for the owner to do, and those procedures agree with each other far more than the brands' reset advice does. What follows is that shared procedure, with the brand-specific warnings where they exist, and the point at which each manufacturer says to stop.

Before you touch anything

Switch off at the wall. If the machine is integrated and the socket is behind a neighbouring cupboard, find it; the panel button does not remove power from the board.

Then wait, if the programme stopped part way through. Bosch warn that the water left in a machine that aborted a hot programme may be very hot and carries a risk of scalding, and put the wait at an hour. Miele carry the same warning in their drain pump guidance, Hotpoint and Samsung in theirs. AEG add a second hazard: undissolved dishwasher tablet in that standing water is strongly alkaline, so wear gloves.

Bail the standing water out with a jug and finish with a sponge until you can see the floor of the tub. You cannot inspect anything through dirty water, and lifting the filter with the tub full puts the water on the kitchen floor.

Not draining: the path, in order

The filter assembly. Lift out the bottom basket and twist the filter anticlockwise to release it. It is two parts — a coarse cup and a fine mesh cylinder — and Bosch, Hotpoint, LG, Samsung and Miele all make the same point in different words: take it apart. Rinsing the assembly whole cleans the coarse cup and leaves the mesh, which is where congealed grease sits, exactly as it was. Scrub both under a hot tap with a washing-up brush until light passes through the mesh. While it is out, check the spray arms turn freely and the jets are clear; Bosch attach that check to their E22 filter code because blocked jets produce the same poor results.

The pump recess. Look into the hole the filter came out of before you put a hand anywhere near it. Bosch warn that the pump may be blocked with glass fragments and that there is a risk of cutting yourself; AEG and Miele say the same. Use a torch, and a cloth rather than bare fingers. A shard of glass, a fruit stone or a fragment of crockery jamming the impeller is the commonest thing found here, and removing it costs nothing. Miele publish the impeller check step by step, with separate articles for G 1000 to G 6000 machines and for the G5 and G7 generation from 2019, and they say that if the impeller turns freely by hand and the pump is still silent, that is the point to stop and book a repair.

The pump cover. Refit the cover so it clicks positively into place, and seat the filter until it locks. Bosch list a loose pump cover as a cause of E24 in its own right, and on an AEG a filter left unseated produces i23, the pump cover code, which looks like a new fault.

The hose. Pull the machine forward if you can and check the waste hose along its whole run for kinks and crushing, and feel for a soft blockage where it meets the waste.

The sink. Run the kitchen tap and watch. If the sink drains slowly, the dishwasher is not the problem: it shares that waste, and a part-blocked trap backs the machine up. Clear the trap first, with a bucket under it. Hotpoint's own advice for F03 sends you to the under-sink plumbing, and Miele point out that a slow-onset restriction — silt in a corrugated hose, a trap slowly closing — times the machine out rather than stopping it dead.

The blanking plug. If the machine has never drained properly since it was installed, or since the kitchen was done, this is almost certainly it. The spigot on the sink waste that the dishwasher hose connects to is supplied sealed, and the blanking plug has to be cut or knocked out. Bosch name a sealed connection as one of their three causes of E24; LG say to treat a never-drained machine as an installation problem before anything else. It is free, and it is booked as a repair far more often than it should be.

Not filling: the path, in order

The tap. Under the sink, on the flexible hose, there is usually a small lever valve, and it gets knocked by whatever is stored in that cupboard. Turn it right off and right back on rather than judging by the handle, and check any second isolation valve on the run.

The hose, by eye first. A dishwasher inlet hose is not the same thing as a washing machine's. On machines with AquaStop, Aqua-Stop or an equivalent, a mains cable runs inside the sheath to a valve at the tap end, which is why AEG head their warning "Dangerous voltage" and Samsung say the hose must never be cut, however long it is. Damage to the outer sheath — a split, a cut, a crush mark — means the job stops there: tap closed, plug out, and a new hose fitted rather than the old one handled. Shortening or repairing one is not an option.

The gauze filter. Tap closed, the hose comes off at the tap end into a bowl, and there is a small mesh in the connector that silts up. Rinse it until you can see light through it.

The flow. While the hose is off, open the tap into a bucket for fifteen seconds and judge the rate rather than the presence; Hotpoint and Samsung both make that distinction. A dribble is a supply problem, and nothing done to the appliance will change it.

Reconnect and watch. Finger tight plus a quarter turn, the hose straightened behind the machine, and a short programme run with an eye on the joint for weeping.

Where the manufacturers say to stop

The line is easy to draw on a dishwasher because of where things are. The heating element, the circulation pump and the anti-flood float all sit in the base of the machine, under the tub, behind the cabinet, in the tray that collects any water that escapes. Nothing an owner is invited to do goes there.

So the stopping points are these. If the filter is clean, the recess is clear, the hose is free and the sink drains, and the code returns, the drain pump is the next candidate, and replacing it is the engineer's job: the code pages put it at roughly £90 to £180 fitted on most brands and £140 to £260 on a Miele. If the tap runs freely, the gauze is clean and the machine still reports no water, the inlet valve is the candidate, at roughly £85 to £155 fitted, and an AquaStop hose assembly is replaced rather than repaired. If the machine drains but you have found water under it, or if the code changes to one of the anti-flood family while you are working, you are no longer looking at a blockage. Isolate and stop.

And one piece of advice to refuse. The most repeated fix online for a dishwasher with water in it is to tilt the machine backwards to drain the base and drop the float. Bosch's manual says to transport the appliance upright only, to prevent residual water running into the controls; Candy say the overflow device depends on the machine sitting level and undisturbed, and that if it must be moved the cycle should be complete and no water left inside. There is a heating element and a float switch in that tray. Water poured across them is how a drain fault becomes an electrical one.

What it usually costs

The honest figure for this pair of codes is nothing. The code pages for every drain and fill code on this site start their range at zero because a filter, a hose, a sink trap and a blanking plug cost nothing to put right, and the manufacturers' own procedures are aimed at exactly those. The symptom pages for a dishwasher left with water in the bottom and for dishes coming out dirty carry the same ranges. When a part is needed it is a pump or a valve, and the figures above are the code pages' brackets rather than quotes: a qualified appliance engineer will price the job after seeing the machine, and on a discontinued model — Samsung no longer sell dishwashers in the UK — parts availability may decide it.

Sources

The procedures are the manufacturers' own owner steps, as recorded on the code pages for Bosch E24 and E22, Hotpoint F03 and F06, AEG i20 and i10, LG OE, Samsung 5C and 4C and Miele F11, each of which cites the Bosch and BSH support articles and GB manual, the Hotpoint UK error-code page, the AEG support articles, the LG owner's manual, the Samsung UK information-code page and manual, and Miele's drain pump articles. The scald, glass and alkaline warnings are quoted from those documents. The "transport upright" instruction is from the Bosch GB manual and the levelling warning from Candy's manual. Cost brackets are the code pages' own.