The short answer
Water left standing in the tub on this platform is nearly always mechanical and nearly always reachable. The single cylindrical filter and the small non-return flap beneath it sit together in the sump, and between them they account for most of these calls. Note the distinction that matters here: water standing in the tub is a drain restriction, while a pump that runs endlessly with a dry tub is flood protection and a different page.
What you are seeing
- Water stands in the tub at the end of every cycle — Note: A restriction in the drain path. Filter, flap, hose or pump, in that order of likelihood.
- The pump runs endlessly with the tub dry and never fills — Note: That is flood protection, not a drain fault. Read the cycle page.
- Dirty water appears in the tub between cycles — Note: The non-return flap is not seating, so drain water is coming back in.
- A little clean water always sits below the filter — Note: That is normal. The sump is designed to hold a small amount to keep the seal wet.
- It drained fine until the sink waste was replaced — Note: The knockout plug in a new disposal or waste fitting was very likely left in place.
- The machine drains but very slowly and noisily — Note: Something solid is against the drain impeller, which is the noise page as much as this one.
Ranked causes on this brand
- Cylindrical filter clogged — Why this rank: First because it is the only filter in the machine, it holds a great deal before it blocks, and that generosity is exactly why owners go years without cleaning it and then arrive here.
- Non-return flap in the sump held open or seized — Why this rank: Second because it sits directly under the filter where debris settles, and because a flap that will not seat causes both slow draining and dirty water returning between cycles.
- Drain hose kinked, or pushed too far into the standpipe — Why this rank: Third: the hose is folded behind the machine every time it is pulled out and pushed back, and a hose driven deep into a standpipe siphons and blocks.
- Waste disposal or sink waste knockout plug still in place — Why this rank: Fourth, but first by a wide margin if the complaint started immediately after plumbing work. A brand-new waste fitting arrives with the dishwasher spigot blanked off.
- Drain impeller obstructed by glass, a stone or a label — Why this rank: Fifth because it usually announces itself with a grinding noise before it stops the machine outright.
- Drain pump failed — Why this rank: Last because everything above it is more common and free to check, and because a pump on a discontinued badge is cross-referenced rather than ordered by name.
What to check, in order
- Confirm there is water standing in the tub — Why: If the tub is dry and the pump runs, this is not a drain fault at all and the cycle page applies instead.
- Bail the standing water out and twist the filter out — Why: Everything worth checking is under it, and it cannot be inspected with water in the way.
- Look at the flap in the sump and check it hinges freely and seats flat — Why: A flap held open by a fragment explains both slow draining and dirty water returning.
- Follow the drain hose behind the machine looking for a kink or a crushed section — Why: This is the cause most often created by the last person who pulled the machine out.
- Ask when the problem started and whether any plumbing was done just before — Why: A knockout plug left in a new disposal is instantly diagnosed by that question and by no other.
Checks you can do safely
- Switch off at the isolator, open the door and bail the standing water out of the tub with a jug and a sponge until the sump is visible. — Tools: jug, sponge, towels — Time: twenty minutes
- Twist out the cylindrical filter assembly, wash it under a hot tap with a soft brush until light passes evenly through the mesh, and set it aside. — Tools: soft brush — Time: a quarter of an hour
- With a torch, clear the sump floor of glass, stones, seeds and labels using a plastic scoop, then check the non-return flap hinges freely and lies flat when released. — Tools: torch, plastic scoop — Time: twenty minutes
- Pull the machine forward far enough to see the drain hose and straighten any kink, making sure the hose rises to a high loop before it falls to the waste. — Tools: none — Time: twenty minutes
- Check the waste connection at the sink. If a disposal or waste fitting was recently installed, confirm its dishwasher knockout plug was removed. — Tools: torch, bucket — Time: a quarter of an hour
- Refit the filter with a full twist until it locks, run the shortest program and watch the drain step from start to finish. — Tools: none — Time: one short cycle
Before you open anything
Safety
Switch off at the isolator before reaching into the sump, and assume there is broken glass under the filter: use a torch and a plastic scoop, never a bare hand swept around blindly. Standing water in a machine that has heated is hot enough to scald, so let it cool before bailing. Put a towel and a shallow tray under the drain hose before disconnecting anything, because the hose holds water above the level of its connection. The inlet hose carries mains wiring in its outer sleeve to a solenoid at the tap end and must never be cut or repaired. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. — Id: unplug-before-service
Where the service line falls
The filter is clean, the flap seats, the hose is clear and looped, the waste is open, and the tub still holds water. The drain pump makes no sound at all during the drain step, which points at the pump or its supply rather than at a restriction. The pump grinds loudly and drains slowly after the sump has been cleared, which suggests a damaged impeller. Water returns into the tub between cycles even with a clean and free-moving non-return flap. The pump has to be replaced, because on a discontinued badge it is cross-referenced to a group-sibling platform by flange and connector rather than ordered by brand.
Nearest pages
What this page does not cover
This page is generalized across families and models on this European built-in platform and describes the single-filter sump with a non-return flap common to it. It does not cover a specific model family, and it does not cover variants with a macerator ahead of the drain pump or installations plumbed to a pumped waste system rather than a gravity waste. Identify your machine from the rating plate on the edge of the door or inside the tub rim rather than from the badge, because this manufacturer supplied the same platform under several group badges and a parts desk cross-references by platform, not by name.
Links down: - [Fagor Dishwasher: Odor or Mold](/blog/fagor-dishwasher-smell-mold) - [Fagor Dishwasher: Abnormal Noise or Vibration](/blog/fagor-dishwasher-abnormal-noise)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
