What U3 Means
U3 is not really a problem in the drawer that shows it. F&P describes it as advisory only, and not displayed to the customer: the other tub in a double DishDrawer has thrown a problem serious enough to disable the shared power supply, and this drawer is reporting that it has been shut down as a consequence.
Common Causes of U3
- A problem in the companion tub that has disabled the shared supply
- An earth leakage or power supply problem detected by the other drawer
- The other drawer locked out and still holding its own code
🔧 One Safe Check You Can Try
Do not spend time on the drawer showing U3 - look at the other one. Whatever code that tub is holding is the problem that actually needs attention, and clearing it is what brings this drawer back.
⚠ Why You Shouldn't Go Further Than That
- Whatever the companion tub has flagged should be established before either drawer is switched back on, since the shutdown was a protective response rather than a glitch.
- Pulling the drawer showing U3 apart is time spent on the healthy half of the machine.
- The two tubs share a mains filter board and supply, so a repair that treats them as independent appliances can miss the actual problem entirely.
- Forcing the supply back on to get one drawer working defeats the interlock that took it down in the first place.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.