What does a slowly leaking dishwasher cost?
Updated August 2026
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A dishwasher that leaks slowly does its worst damage out of sight: water wicks into the subfloor and the cabinets beside it, warping floors and breeding mold for a $500–5,000 repair long before a puddle ever reaches the open floor. The parts that cause it are cheap, a $20–50 door gasket or a $15–40 supply or drain hose, and both are DIY. Catch the seep early and it is a twenty-dollar afternoon; miss it and you are replacing flooring and a cabinet base you cannot see rotting. A slow leak is the expensive kind precisely because nothing puddles where you would notice. Here is the escalation from a worn seal to a gutted cabinet.
The escalation ladder
Every row below is the same leak, left a little longer. The top is a cheap warning; the bottom is a claim.
| What happens | Typical bill | How fast |
|---|---|---|
| You spot the seep and replace the door gasket | $20–50 part, about an hour DIY | Same day |
| A cracked supply or drain hose is swapped instead | $15–40 part, under an hour DIY | Same afternoon |
| You call a tech to find and fix the leak | $150–300 service call | 1 visit |
| Water wicks into the subfloor under the unit for months | $500–1,500 to dry out and replace warped flooring | 3–6 months |
| Rot and mold spread into the adjoining sink cabinet | $1,500–5,000 for cabinet, subfloor, and remediation | 6–12 months |
| The leak reaches a finished basement or ceiling below | $3,000–8,000+ once drywall and framing are involved | Once it travels |
Warning signs
Because a slow dishwasher leak hides under the unit, you hunt for indirect tells. Flooring that is cupped, lifted, or discolored right in front of the dishwasher or at the base of the adjacent sink cabinet is the classic sign, along with a persistent musty smell in that corner of the kitchen. Open the cabinet under the sink and feel the shared wall and floor for damp or soft spots, and look for a rusty ring or water stains under the dishwasher's toe-kick. A door that has started leaving a thin puddle at the front, or detergent residue crusting along the bottom of the gasket, points straight at a failed seal. Damp, dark, or spongy is the warning, and it precedes any obvious flood.
The prevention math
Prevention is a two-minute look under the toe-kick and behind the unit every time you clean the filter, plus a $20–50 gasket or $15–40 hose the moment one shows wear. Feel the water inlet valve and both hose ends for dampness, replace a gasket that is stiff, torn, or crusted, and keep the sink-cabinet shutoff working so you can kill the supply fast. That habit costs nothing and swaps a $500–5,000 floor-and-cabinet job for a cheap part. Pair it with the routine in how often to clean a dishwasher filter, and weigh the machine's odds with how long a dishwasher lasts.
Every line in that table starts with a skipped 10-minute task. OnOtto keeps the 10-minute version on your calendar so the $2,000 version never happens.
Get the nudge before the billFrequently asked questions
How do I find where my dishwasher is leaking from?
Work from most to least common. Pull the bottom rack and inspect the door gasket for tears, gaps, or hardened spots, then run a short cycle and watch the door edges for weeping. Next, remove the lower toe-kick panel and shine a light underneath during a cycle to spot drips at the water inlet valve, the supply line, the drain hose, and the pump seals. Food packed under the door or an overloaded detergent dose can also force water past the seal, so rule those out first.
Is it safe to keep running a dishwasher that leaks a little?
No. Even a minor seep feeds water into the subfloor and cabinet every cycle, and the damage compounds while you wait. Shut off the water at the sink-cabinet valve, stop using the machine, and fix the source before running it again. If you cannot find or fix the leak quickly, a $150–300 service call is far cheaper than the $500–5,000 in floor and cabinet damage a chronic leak causes. Running the machine wet also risks the electrical components at the base.
How much does it cost to fix a leaking dishwasher?
The part is usually cheap: a door gasket is $20–50, a supply or drain hose is $15–40, and a water inlet valve is $20–60, all within reach of a confident DIYer in under an hour. A technician diagnosing and replacing the failed part runs $150–300. The expensive number is not the repair, it is the delayed one: hidden water damage to flooring, subfloor, and cabinets that reaches $500–5,000 once it has had months to spread unseen.
Should I repair or replace a leaking dishwasher?
If the machine is under about 7 years old and the leak traces to a gasket, hose, or valve, repair it: those are $15–60 parts. If it is past 9 or 10 years, leaking from the tub or pump, and the repair quote climbs toward $250 or more, replacement (a $600–1,200 machine) usually wins. Weigh the fix against the age and the risk of the next leak, and check how often to replace a dishwasher for the age thresholds.