UB
Samsung Dishwasher
Severity: MinorWhat Does This Error Mean?
The UB error on a Samsung dishwasher means 'Unbalanced' — the spray arm or dish rack is unbalanced or blocked. This usually means a tall item is sticking up through the rack and hitting the spray arm as it rotates. The control board detects that the spray arm can't complete its rotation and triggers UB. This is not a mechanical fault — simply rearranging your dishes fixes it in seconds.
Affected Models
- Samsung DW80R9950UG
- Samsung DW80R5061US
- Samsung DW80K5050UG
- Samsung DW80J3020US
- Various Samsung dishwashers
Common Causes
- A tall glass, pot handle, or utensil sticking up and blocking the upper or lower spray arm
- A bowl or container loaded upside-down catching water and tipping to block the spray arm
- A rack tine that was bent or a broken rack section snagging the spray arm
- The spray arm itself partially detached from its mount and wobbling into obstruction
- A foreign object (fallen from a rack) lying on the bottom blocking the lower spray arm
How to Fix It
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Open the dishwasher door and cancel the cycle. Look at the upper and lower spray arms — the spinning plastic pieces that spray water onto the dishes. Manually spin each spray arm by hand to check for any obstruction. Both arms should rotate freely through a full 360 degrees.
The lower spray arm is at the bottom of the tub. The upper spray arm is underneath the upper rack.
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Check the upper rack for any tall items sticking down below the rack level. Wine glasses, tall cups, or mixing bowls loaded too low can hang below the rack and block the upper spray arm. Rearrange these items so nothing extends below the rack wire.
Tall items in the upper rack should face down and inward, and shouldn't extend past the bottom of the rack tines.
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Check the lower rack for items sticking up above the rack level. Pot handles, spatulas, or large serving spoons sticking up can block the middle or upper spray arm. Lay these flat in the utensil basket or on the top rack instead.
Long utensils in the utensil basket should always be placed handles-up (spoons and forks handles-down for safety, but spatulas and tongs horizontally).
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Check the bottom of the tub for any items that fell off the rack. Lids, small containers, or bottle caps sometimes fall through the rack and land on the tub floor directly in the path of the lower spray arm. Remove anything lying loose on the tub floor.
Lightweight plastic items are especially likely to fall through racks. Place them in the upper rack or clip them in place.
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After rearranging, confirm both spray arms spin freely, then close the door and restart the cycle. The UB error should not return if the obstruction has been cleared.
If UB appears again immediately, open and recheck — the problematic item may not have been obvious the first time.
When to Call a Professional
UB almost never requires a technician. If rearranging the dishes and checking the spray arms doesn't clear the error, a spray arm mount may be broken. Spray arm replacement is an inexpensive DIY repair — arms typically cost $15-$30 and simply unscrew or snap on. Only call a technician if the spray arm mechanism beneath the arm mount is damaged.
Frequently Asked Questions
Can the UB error damage my dishwasher?
No — when a Samsung dishwasher detects the spray arm is blocked, it stops the cycle immediately. This protects both the spray arm mechanism and the dishes from being damaged by a spinning arm hitting them. The UB code is entirely a protective feature — not a sign of any mechanical damage.
My dishwasher shows UB but there's nothing blocking the spray arm — why?
If the spray arms spin freely and nothing is in the way, the UB may be caused by a spray arm that's become loose on its mount. A spray arm that wobbles side to side (rather than spinning flat) can trigger the UB sensor. Check the spray arm's center mount — it should sit flat and click into place securely. Replace the spray arm if the mount is cracked or won't hold the arm flat.
Are Samsung dishwasher spray arms easy to replace?
Yes — spray arms are one of the easiest dishwasher parts to replace. The lower spray arm usually just lifts off or unscrews with a quarter turn. The upper spray arm typically snaps out with light pressure on the center nut. Replacement arms cost $15-$35 and are available on Amazon or from Samsung parts suppliers. No tools are required for most models.