What Moisture Sensor Disconnect Means
One flash of the Pots & Pans Wash light followed by one flash of the Normal Wash light is the base-pan moisture sensor reading outside its normal range - disconnected rather than wet. Viking's FDB451 fail-code table (2012, page 12) keeps this separate from the water-detection alarm, which flashes both lights continuously instead.
Common Causes of Moisture Sensor Disconnect
- Wiring to the base-pan moisture sensor disconnected
- Moisture sensor itself has failed
- Control board misreading a sound sensor
🔧 One Safe Check You Can Try
No home repair here, but the distinction is worth knowing before anyone panics: this pattern says the leak sensor is not reporting properly, not that water has been found. The sensor lives in the base pan, so if the machine has recently been moved or re-leveled, mention that when you book.
⚠ Why You Shouldn't Go Further Than That
- A leak sensor that is not reporting leaves the machine with no flood protection, so running loads meanwhile removes the very thing that would catch a small leak before it became a cabinet repair.
- The sensor and its harness sit in the base pan directly under live connections, so looking for either means the machine dead at the breaker and drawn out.
- Viking gives the sensor a nominal 175 kilohm reading taken at named control-board pins, which is not a check that can be made by eye at the plug.
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.