What to check yourself
Step 1. Clean the filter, both parts of it
This alone ends about half of all OE cases, and the reason it fails so often is that people clean one half. Pull the racks out, lift the cylindrical filter cup straight up without twisting, and underneath you will find a flat fine mesh plate that most owners have never seen. Both need rinsing. While the filter is out, put your hand in the sump and feel for glass, a fruit sticker, a toothpick or a shard of bone sitting over the pump inlet.
Broken glass in the sump is the usual reason people cut a finger doing this. Look before you reach in, and use a torch.
Step 2. Check the drain hose for a kink and for the high loop
Pull the machine forward and follow the hose the whole way. Two things matter: no crushed section against the wall, and a rise up to counter height before the hose drops to the disposal or the drain. That loop is what stops sink water running back into the machine, and it goes missing surprisingly often after a kitchen refit.
Step 3. If the disposal is newer than the dishwasher, check the knockout plug
This is the one that catches people out completely, because the machine worked fine last month. A new garbage disposal ships with a plastic disc sealing the dishwasher inlet, and it has to be punched out during installation. If it was missed, the dishwasher has nowhere to send its water. Look at the hose spigot on the disposal: a plug still in place is obvious once you know to look.
Step 4. Clear the air gap if the sink has one
The small chrome cylinder next to the tap. Twist the cap off, lift the cover and look inside for the grey sludge that builds up there. It blocks quietly and gives exactly this code.
Step 5. Listen for the pump before you buy one
Start a cycle and put an ear near the bottom of the door. A hum or a whine means the pump is being driven and the obstruction is somewhere ahead of it, so keep looking at hoses and filters. Total silence points at the pump itself, its wiring or the board, and that is where the free repairs end.
What a technician will look at
Described so you know what you are paying for, not as steps to repeat.
Test or replace the drain pump
The pump sits under the tub base and is reached from underneath, which means pulling the machine out and laying it back. A technician meters the coil: an open circuit or a dead short both mean replacement. The part itself is not expensive, the access is what you are paying for.
When to call a technician
When the filter is clean, the hose runs properly with a high loop, the disposal plug is out, and OE still comes back. At that point the fault is inside the machine rather than in the plumbing around it, and everything left needs the appliance moved and powered while open.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Cleaning the filter and clearing the sump | - | Free |
| Punching out the disposal knockout plug | - | Free |
| Drain pump replacement | $20 to $100 | $150 to $400 |
| Diagnosis alone, if you stop there | - | $75 to $130 |
A new machine of the same class runs $500 to $1,500. Once a quote passes about a third of that on an older appliance, the repair stops making sense.
Codes people confuse this with
Questions people ask
- There is water in the bottom. Can I just bail it out and run it again?
- You can bail it out, and you should before working underneath, but running it again changes nothing. The machine will fill, wash, try to drain, fail at the same point and show OE again. Find the blockage first.
- A little water always sits in the bottom. Is that the same problem?
- No. A small amount in the sump, roughly a cupful, is normal and deliberate: it keeps the seals from drying out. OE means the machine still had a tub full at the end of the cycle, which is a different picture entirely.
- My LG washing machine shows OE too. Same fault?
- Same idea, different appliance and different parts. Both mean the machine could not get rid of its water. The filter, the pump and the hose are all in different places, so do not carry a diagnosis from one to the other.
- How often should the filter actually be cleaned?
- Once a month if you scrape plates before loading, every couple of weeks if you do not. It takes about two minutes and it is the single thing that prevents this code.
Which machines this applies to
Applies to
LG dishwashers across the LDF, LDT, LDP and LSDF ranges, front control and top control alike. The same two letters on an LG washing machine also mean a drain fault, so that one is easy to remember.
Last checked
2026-08-10