What's Causing That High Water Bill? Common Plumbing Leaks to Check

Step one: read your meter. With nothing running in the house, the meter dial should be still. If it's moving, you have a leak somewhere. That's exactly the test Phoenix Plumbing Co. starts every high-bill call with.

Most common culprit: a leaking toilet flapper. Put dye tablets in the tank — if color shows up in the bowl without flushing, that's your leak.

Second most common: outdoor irrigation. Run each zone separately and watch for soaked spots or pressure drops.

Less common but expensive: slab leak. Warm floor spots, sounds of running water, or mildew smells are the signs — call our leak detection team before you tear up a single tile. If we confirm a slab leak, our pipe repair and replacement crew handles the fix, usually re-routing rather than jackhammering the floor.

One more thing worth ruling out: if you've checked the toilet flapper, the irrigation box, and the hose bibs and your bill is still climbing, the leak may be under your foundation. Warm spots on the tile, the sound of running water at night, and damp baseboards are the giveaways. We put together a full guide on how to know if you have a slab leak.

A high bill paired with weak showers is a combination worth taking seriously, because a hidden leak steals pressure and money at the same time. Learn how to tell a harmless clogged aerator from a leak that needs attention today in why is my water pressure so low in Phoenix.

A creeping water bill is the polite version of a plumbing problem. The impolite version is a pipe that splits open inside a wall, and the same aging lines cause both. Take five minutes and read what to do if a pipe bursts in your house so you are not learning it while water runs down the hallway.

The single most common culprit behind a mystery water bill is a toilet quietly refilling itself all day and night. A worn flapper or a stuck fill valve can waste hundreds of gallons a day without a puddle anywhere. Learn how to diagnose it with a two-minute dye test in our post on why your toilet keeps running.

The best defense is not needing us at 2 a.m. — an annual plumbing inspection catches most of these leaks while they're still $50 fixes.