What to check yourself
Step 1. Check you are using HE detergent
This is the big one. A high efficiency washer uses a fraction of the water an old one did, and ordinary detergent foams uncontrollably in it. Look for the HE symbol on the box. Regular detergent in an HE machine produces this code on essentially every wash, and no amount of maintenance will change that.
Step 2. Halve the dose, then halve your idea of the right dose
The amount printed on the box assumes a heavily soiled full load in hard water. Everyday laundry needs about half of it and light loads less again. One to two tablespoons of HE detergent covers most loads. This single change fixes the fault permanently in most households.
Step 3. Let the machine finish rather than restarting it
The suds routine is already running. Cancelling and starting again interrupts it and begins the whole process from the top, which is why the cycle sometimes seems to run forever.
Step 4. Flush out the residue that has built up
If the code appears even on correct doses, there is old detergent in the dispenser, the hoses and the drum. Run a rinse and spin with nothing in it, then a self clean or drum clean cycle with a washer cleaner, and wipe out the dispenser drawer and the door seal by hand.
Step 5. Clean the debris filter
A partly blocked filter keeps water moving slowly, and slow moving water holds foam. Clearing it removes the condition that lets suds build in the first place.
When to call a technician
Almost never. If heavy foam appears with no detergent at all in a machine you have already flushed out, the foam or level sensor may be misreading, and that is worth a call. Everything else here is dosing.
What the repair costs
| Repair | Part only | Fitted by a technician |
|---|---|---|
| Using less detergent, switching to HE | - | Free |
| Sensor replacement, in the rare case it is the machine | - | $150 to $350 |
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
- Why does it say 5UD instead of SUD?
- Because the display cannot draw a letter S. Seven segment digits render it as a 5, so SUD becomes 5UD and Sd becomes 5d. It is the same code and the same answer.
- Can suds cause other faults?
- Yes, and this is worth knowing. Heavy foam stops the pump moving water properly, so a drain code often appears alongside it, and foam pushed past the door seal can trigger the leak code. Fix the dosing and both usually disappear with it.
Which machines this applies to
Applies to
All Samsung high efficiency washers. The display draws the letter S as a 5 on many panels, which is why SUD, 5UD, Sd and 5d are all the same code.
Last checked
2026-08-09