Leaking Restaurant Kitchen Sink: Finding the Leak and Replacing the Part

A drip under a kitchen sink in a working restaurant is easy to ignore until the cabinet floor is soaked, the floor under the line goes slick, or an inspector notices it. The cause is rarely dramatic. A strainer basket gasket dries out, a trap joint loosens, a supply line or stop valve weeps, or a drain connection shifts after months of dishwashing vibration.

The harder part is that the water you see is often not where it starts. It runs along a pipe and drips from the lowest point.

We open up the plumbing under the sink and run water through each part in turn. Fill the sink and let it drain, then run the faucet, then each supply. The leak shows itself when the part that is failing is the one under load.

If the drip stops at one connection but starts again when we run the sprayer or the next sink, there may be two leaks, and we check them separately. We also look at the wall and floor under the sink for older moisture, because a slow leak that has run for weeks changes what we need to replace.

Most of these are a same-visit repair: replace the strainer or gasket, rebuild or replace the trap, swap the supply line or valve, and test again under load. If an older pipe section is corroded or split, we cut out and replace that section and tell you what we found.

If the sink base, a wall connection or a drain that goes through the floor is involved, the work gets larger. We stop the leak first with a temporary fix if one is safe, then write a proposal for the permanent repair with the price before work starts.

Take a photo of the leak and note where the water ends up. If the sink is a food-prep sink, remember the Food Code and Maricopa County rules for indirect drains: some of these sinks must drain through an air gap rather than a direct connection, so the repair has to keep that arrangement.

Chain and managed locations may require a vendor check-in, a PIN or a work order number, and the order often has a not-to-exceed limit. Tell us when you call. We also take before-and-after photos for sites that ask for them.