Dishwasher leak — do this now
- Shut off the dishwasher water supply — valve is usually under the sink next to the dishwasher inlet line.
- Stop the cycle and shut off power at the breaker.
- Pull the dishwasher forward if possible — most leaks only show from behind or under.
- Check for hidden damage: cabinet toe-kicks, flooring at the dishwasher base, wall behind the dishwasher, subfloor under cabinets.
- Call Vault at (385) 250-2825 if cabinet or flooring shows signs of chronic water exposure.
- Photograph everything for insurance.
Why dishwasher leaks are deceptively bad
Dishwashers sit in a cabinet opening recessed into the kitchen countertop. Water that leaks from the inlet, drain, or door runs down the sides and underneath — into the cabinet cavity, under the subfloor, and sometimes into the wall cavity behind. By the time you see a puddle on the kitchen floor, water has usually been under the dishwasher for weeks or months.
Common dishwasher leak sources
Supply line leak
The hot water supply line enters from the back or side. Connections at the house supply valve, inlet valve, or the braided flex line itself can leak. Rate: slow drip to steady stream depending on severity. Signs: wet under-sink cabinet, water around the base valve.
Door seal (gasket) failure
The rubber gasket around the door degrades over 7-10 years. Water escapes during the wash cycle. Signs: water on the floor directly in front of the dishwasher, limited to cycle time.
Inlet valve stuck open
The water inlet valve fails to shut off. Dishwasher overflows during fill. Signs: water from the top edge during a wash cycle, longer-than-normal fill time.
Drain hose failure
Flex drain hose cracks or disconnects from the garbage disposal or standpipe. Signs: dirty wash water on the floor during the drain cycle (not the fill cycle).
Tub crack
The dishwasher’s interior tub cracks (plastic ones more often than stainless). Signs: water underneath consistently, visible interior crack if you look.
Pump seal failure
Internal pump leaks into the base. Signs: dishwasher runs noisier, water under the unit, dishes may not get clean.
Clogged air gap
If your dishwasher has an air gap on the countertop, a clog pushes water out of the air gap. Signs: water bubbling from the small cylinder on the sink deck during a wash cycle.
How to inspect for hidden damage
- Open the under-sink cabinet. Look at the floor, the back wall, the cabinet sides. Discoloration, warping, soft wood, musty smell.
- Open adjacent base cabinets. Check toe-kicks and under the toe-kick trim.
- Pull the dishwasher forward (if you can safely disconnect). Look at the floor it was sitting on.
- Check the floor at the dishwasher front — tile grout darkening, hardwood cupping, vinyl bubbling.
- Check the drywall at the back of the cabinet — stains, soft spots.
- Smell for musty — mold often grows under cabinets fed by chronic dishwasher leaks.
What Vault does on a dishwasher-leak call
- Moisture map the affected area with meters and infrared.
- Confirm damage extent — under-cabinet floor, subfloor, drywall, adjacent cabinetry.
- Remove damaged flooring, drywall below waterline, saturated cabinet toe-kicks.
- Air movers + dehumidifier to IICRC S500.
- Antimicrobial treatment, mold inspection if dwell time > 48 hours.
- Reconstruction — same crew handles cabinetry repair, flooring, drywall.
Typical cost
| Scope | Typical range |
|---|---|
| Small puddle, caught early, cabinet dry | $450-$1,500 |
| Localized damage to flooring + cabinet toe-kick | $1,500-$3,500 |
| Chronic leak, mold under cabinet, floor replacement | $3,500-$8,500 |
| Water migrated to adjacent cabinetry + wall | $5,500-$12,000 |
Insurance
Sudden burst or sudden failure: covered. Chronic drip over months: often disputed as deferred maintenance (homeowner should have noticed). Dishwasher itself: not covered under homeowner’s.
Prevention
- Replace braided stainless supply hose every 10 years
- Install a water leak detector in the under-sink cabinet
- Inspect the door gasket annually — replace at first signs of cracking
- Keep the dishwasher drain hose high-looped per manufacturer instructions
- Air gap: run disposal before dishwasher drain cycle
Dishwasher leak with hidden damage suspected?
Call (385) 250-2825. We’ll find what’s under and behind the dishwasher.
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Water coming in right now? Our emergency water damage service in Provo answers live 24/7 at (385) 250-2825.