Most homeowners think about water damage in dramatic terms. A burst pipe, a flooded basement, a roof torn open in a storm. What they don’t picture is the dishwasher.
But some of the worst water damage I’ve walked into wasn’t caused by a single catastrophic event. It was caused by a slow drip behind a dishwasher, or a leaking supply line under a refrigerator, that nobody noticed for three months. By the time the smell gave it away, the subfloor was soft, the drywall was rotted at the base, and mold had colonized the wall cavity.
Appliance leaks are quiet. That’s what makes them dangerous.
Where Appliance Leaks Actually Start
Dishwashers are the most common offender. The supply line and drain hose at the back of the unit, the door gasket that wears out over years, the float assembly inside the tub — any of these can fail gradually. Water doesn’t spray dramatically. It seeps. It runs along the cabinet frame, wicks into the particle board underneath, and pools under the flooring.
Refrigerators with ice makers have a supply line running to the back of the unit. These lines are often plastic and they get brittle over time. A small pinhole in that line can drip for months in a space no one ever looks at. Same story with washing machines. The supply hoses behind your washer are under constant pressure, and they can fail at the connection point or crack along the hose body. Most manufacturers recommend replacing rubber washer hoses every five years. Most homeowners have never replaced them at all.
Water heaters are a separate category, but worth noting: a failing water heater typically shows signs before it fails completely. Rust-colored water, a visible corrosion ring at the base of the tank, moisture under the unit. These are not normal. They’re warnings.
The Problem Isn’t Always Where the Water Is
This is what catches people off guard. You might notice a soft spot on the kitchen floor and assume it’s localized to that area. But water travels. It follows the path of least resistance through subfloor, under flooring transitions, along joists, and down into lower levels. A supply line leak behind a dishwasher can eventually show up as a moisture problem in the basement ceiling below.
By the time there’s visible staining, warping, or a musty smell, the moisture has already been there long enough to support mold growth. Mold starts forming in as little as 48 to 72 hours under the right conditions. A slow leak that’s been running for weeks creates ideal conditions well before you’d ever notice the smell.
What to Do When You Find It
If you catch the appliance in the act — water actively coming from the unit — turn off the supply valve. Every dishwasher, washing machine, refrigerator with an ice maker, and water heater has an accessible shut-off nearby. If you can’t find it or it won’t turn, shut off the main water supply to the house.
Then stop. Don’t pull up the flooring to check underneath. Don’t stuff towels into the cabinet and call it handled. What you do in the next few hours matters for your insurance claim.
Take photos and video of everything you can see. Document the appliance, the visible moisture, any staining or discoloration on flooring and cabinets. This is your evidence before anything gets moved or cleaned up. Then call your insurance company to report a water loss.
After that, call a certified restoration company. The visible moisture is rarely the full picture.
What Professional Assessment Actually Finds
I’ve been on jobs where a homeowner pulled up the kitchen floor themselves, saw a few inches of soggy subfloor, replaced it, and thought they were done. Then called us six months later because the musty smell came back and the new floor was starting to lift.
The subfloor was dried. The wall cavities behind the cabinets were not.
An IICRC-certified restoration team uses moisture meters and thermal imaging to map where the moisture actually went. The readings show what the eye cannot. Once the full extent of the damage is documented, a proper drying plan is set using calibrated equipment, and moisture levels are logged daily until everything reaches acceptable readings. That drying log is what your insurer needs to close the claim correctly.
Appliance leaks are typically covered under standard home insurance policies as sudden and accidental water losses, provided the damage isn’t due to long-term neglect. Documenting the loss promptly and working with a company that produces Xactimate estimates gives your adjuster the documentation needed to move the claim forward.
A Note on Preventive Habits
Check under your dishwasher and refrigerator once a year. Pull out the units slightly and look at the supply lines. Any discoloration on the floor, soft spots in the cabinet base, or visible moisture is a reason to investigate further. Washing machine hoses should be inspected for cracks, bulging, or rust at the connectors.
None of this takes more than fifteen minutes annually. The alternative is finding out the hard way, the way most people do, when the damage is already well underway.