The base-pan float switch is a leak-protection feature built into Thermador dishwashers, designed to detect water where it shouldn’t be and shut off the water supply automatically. When it triggers — showing as E15 — it’s worth understanding what’s actually happening.
It’s a Feature, Not a Bug
This safety switch exists specifically to prevent the kind of slow, undetected leak that can cause serious water damage to flooring, subfloors, and cabinetry long before a homeowner notices.
The Right Response
Turn off the water supply valve immediately, and don’t attempt to reset and rerun a cycle to see if it clears on its own. Even if the trigger turns out to be a false alarm, running the appliance again before confirming that is an unnecessary risk.
Real Leak vs. False Trigger
The float switch is sensitive enough that even a small amount of residual water can keep it triggered — distinguishing a false alarm from a real leak reliably requires a technician’s inspection, not a guess.
Bottom Line
Treat every base-pan alert as a genuine leak until proven otherwise. Book a visit through our dishwasher repair page.
Not Confident Doing This Yourself?
A factory-trained technician can diagnose and fix it safely, usually same-day.