The short answer
On a Cove dishwasher that has been in service for years, a leak usually means a gasket that has hardened or a fitting that has relaxed through heat cycling, rather than an installation error. On this class of machine the leak is worth chasing promptly: water under fitted cabinetry costs far more than the repair does.
What you are actually seeing
- A small leak that has grown gradually over months — Means: on-page
- The door gasket feels hard and stays compressed when pressed — Means: on-page
- A returning water mark on the cabinet base — Means: on-page
- Leaking only on the longest and hottest cycles — Means: on-page
- A swollen or stained cabinet plinth — Means: on-page
- Water standing inside the tub with a dry floor — Means: different-fault — Go to: cove-dishwasher-drainage-failure
- Condensation under the worktop at the end of a cycle — Means: different-fault — Go to: cove-dishwasher-door-seal
- Body: Match what you see before you take anything apart. A small leak that has grown gradually over months. The door gasket feels hard and stays compressed when pressed. A returning water mark on the cabinet base. Leaking only on the longest and hottest cycles. A swollen or stained cabinet plinth. Some near-miss symptoms belong on a different page: Water standing inside the tub with a dry floor points at a drain fault, covered on cove-dishwasher-drainage-failure; Condensation under the worktop at the end of a cycle points at normal venting rather than a leak, covered on cove-dishwasher-door-seal.
Causes, ranked for this machine
- A door gasket that has hardened and taken a permanent set — Why this rank: First on an older machine because rubber loses its spring with heat cycling, and the door gasket sees more of it than any other seal
- Connections that have relaxed over years of heat cycling — Why this rank: A joint tight for years can weep once the clamp relaxes, which matches a leak that grew gradually
- An aged sump or pump seal weeping only when the machine is hot — Why this rank: Explains a leak that appears on long hot cycles and not on a quick wash
- Cabinetry damage that is now channelling water in a new direction — Why this rank: On an integrated machine a swollen plinth changes where water goes and disguises the source
- Debris in the gasket or over-dosed detergent — Why this rank: Still worth ruling out because it is free, but it ranks lower on a machine whose seal has visibly hardened
- Body: Ranked for a premium built-in dishwasher: hard-plumbed, on a dedicated supply, installed under a worktop by a fitter, quiet by design, with hand-cleaned filtration and a condensation dry that depends on rinse aid. Most likely: A door gasket that has hardened and taken a permanent set. First on an older machine because rubber loses its spring with heat cycling, and the door gasket sees more of it than any other seal. Next most likely: Connections that have relaxed over years of heat cycling. A joint tight for years can weep once the clamp relaxes, which matches a leak that grew gradually. Third: An aged sump or pump seal weeping only when the machine is hot. Explains a leak that appears on long hot cycles and not on a quick wash. Fourth: Cabinetry damage that is now channelling water in a new direction. On an integrated machine a swollen plinth changes where water goes and disguises the source. Fifth: Debris in the gasket or over-dosed detergent. Still worth ruling out because it is free, but it ranks lower on a machine whose seal has visibly hardened.
What to check, in order
- Press the door gasket and judge whether it springs back
- Note whether the leak follows hot cycles only
- Lay paper under the machine and in the cabinet to find the first wet spot
- Look at the plinth and the cabinet base for swelling or staining
- Body: Each check rules out the causes above it. First, press the door gasket and judge whether it springs back. Second, note whether the leak follows hot cycles only. Third, lay paper under the machine and in the cabinet to find the first wet spot. Fourth, look at the plinth and the cabinet base for swelling or staining.
Checks you can safely make yourself
- Press the door gasket along its length and note where it stays compressed rather than springing back — Tools: none — Time estimate: a few minutes
- Run a short cool cycle and a long hot cycle on separate days and note which produces the leak — Tools: notepad — Time estimate: two cycles
- Switch off at the breaker, dry everything and lay paper under the machine and in the cabinet to find the first wet spot — Tools: paper, towel — Time estimate: one cycle
- Open the adjacent cabinet and check every fitting for weeping, tightening only by hand where accessible — Tools: torch — Time estimate: a quarter of an hour
- Look at the plinth and the cabinet base for swelling, staining or a long-standing water mark — Tools: torch — Time estimate: a few minutes
- Body: Checks an owner can make with the machine switched off at the breaker, or by watching a cycle. Step one: Press the door gasket along its length and note where it stays compressed rather than springing back. Tools: none. Time: a few minutes. Step two: Run a short cool cycle and a long hot cycle on separate days and note which produces the leak. Tools: notepad. Time: two cycles. Step three: Switch off at the breaker, dry everything and lay paper under the machine and in the cabinet to find the first wet spot. Tools: paper, towel. Time: one cycle. Step four: Open the adjacent cabinet and check every fitting for weeping, tightening only by hand where accessible. Tools: torch. Time: a quarter of an hour. Step five: Look at the plinth and the cabinet base for swelling, staining or a long-standing water mark. Tools: torch. Time: a few minutes.
Safety first
Safety
Switch off at the breaker before reaching behind or under the machine, and dry the floor before you work. Water under a fitted kitchen can damage cabinetry long before it becomes visible, so treat a returning water mark as urgent even when the volume is small. On a machine of this age, remember that the door carries a custom panel under spring tension set years ago: do not loosen door hardware, and treat any water reaching fitted cabinetry as urgent rather than cosmetic. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. unplug-before-service
Where the owner fix ends
On an older machine, call a technician promptly once the gasket is proven hard or the leak follows hot cycles. A gasket or a seal on a machine of this quality is a worthwhile repair, and the cost of water damage to fitted cabinetry makes delay the expensive option.
Nearest pages of the same kind
Generalized information
This page is generalized across the Cove dishwasher line. Fully integrated machines carrying a custom cabinet panel and machines with a finished front share the ranking above but not every part, and this page does not cover a specific model, control revision or installation. Family- and model-specific pages, where they exist, are linked below.
Links: - [Common COVE Dishwasher Problems](/blog/cove-dishwasher-problems) - [Cove Dishwasher: Abnormal Noise or Vibration](/blog/cove-dishwasher-abnormal-noise-2) - [Cove Dishwasher: Does Not Clean or Dry](/blog/cove-dishwasher-cleaning-performance-2) - [Cove Dishwasher: Controls, Display or Error Code](/blog/cove-dishwasher-control-fault-2)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
