Hello
I found this answer on another site. It sounds like a standard error.
Q: U1 ERROR. The unit is showing a U3 error code.
A: U1 means the unit has failed to prime with water within 3 minutes. Its taking longer than expected to fill with water. Check the fill valve, water supply problem, spray arm not in place, excessive foaming (using hand-dishwashing soap?)
Hope this helps
Lana, July 2007