A water bill that jumps without explanation is almost always a leak — and most leaks waste far more water than people expect. Here's how to systematically find the problem.
First: Check Your Usage History
Log into your KUB account (if you're a Knoxville Utilities Board customer) or your utility's portal. Compare this month's usage to the same month last year. A bill spike is more meaningful than an absolute number — what changed?
KUB provides usage in gallons on your bill. The average Knoxville household uses 2,000–4,000 gallons per month. If your bill shows 8,000 gallons and nothing has changed in household habits, you have a leak.
The Most Common Causes of a High Water Bill
Running Toilet (Most Common)
A running toilet is the single most common cause of unexpectedly high water bills — and it's often silent. A toilet with a failed flapper or fill valve can waste 200 gallons per day. At KUB rates, that's roughly $20–$40 extra per month from one toilet alone.
Test: Add a few drops of food coloring to the toilet tank. Don't flush. Wait 15 minutes. If color appears in the bowl, the flapper is leaking.
Fix: A new flapper costs $5–$10 at any hardware store and takes 10 minutes to install. If the fill valve is also faulty, a complete toilet rebuild kit runs $20–$30 or a plumber can do it for $150–$250.
Dripping Faucet
A faucet dripping once per second wastes approximately 3,000 gallons per year. Faster drips waste more. Check every faucet in the house — don't forget outdoor hose bibs.
Fix: Usually a worn washer or cartridge. DIY-able for most standard faucets; plumber service runs $200–$300.
Leaking Supply Lines
The braided supply lines that connect your faucets, toilets, and dishwasher to the wall shutoff valve can weaken and fail — especially older plastic or rubber lines. Check under every sink and behind every toilet for moisture or mineral deposits (white or rust-colored crust around fittings).
Slab Leak or Underground Leak
If you've checked everything visible and can't find the source, the leak may be under the slab or in the supply line between the meter and the house. Signs include warm spots on the floor, the sound of running water when everything is off, or a meter that keeps moving with all supply shut off.
Irrigation and Outdoor Faucets
If you have an irrigation system, a broken head or a zone valve that doesn't close completely can run constantly without being obvious. Walk the irrigation zones individually and look for water in places it shouldn't be.
Outdoor hose bibs often leak at the packing nut or internal washer, especially after a winter freeze.
Water Softener Stuck in Regeneration
If your home has a water softener, check that it's cycling correctly. A stuck or misconfigured regeneration cycle can run the softener continuously — flushing hundreds of gallons.
How to Test for a Leak Without a Plumber
Step 1: Note your water meter reading. Write it down.
Step 2: Don't use any water for 2 hours. No flushing, no dishwasher, no laundry.
Step 3: Check the meter again. If it moved, you have a leak.
Shortcut: Most modern water meters have a low-flow indicator — a small triangle or dial that spins with even minor flow. If it's spinning with all water off, you're leaking.
When to Call a Plumber
Call Honey Bear Plumbing at (865) 284-2424 if:
- Your meter shows usage with all water off and you can't find the source
- You hear running water in the walls or under the floor
- You have warm spots on a concrete slab floor (slab leak)
- The leak is in a supply line you can't reach or replace yourself
- Your irrigation system needs diagnosis and repair
- You want professional leak detection to confirm the location before opening walls or slab
Frequently Asked Questions
How much does a running toilet add to a water bill in Knoxville?
A toilet with a failed flapper running continuously can waste 200 gallons per day — roughly 6,000 gallons per month. At current KUB rates, that's approximately $25–$45 extra per month from a single toilet.
Can a leaking pipe increase water bill without visible water?
Yes. A slab leak or underground supply leak can lose hundreds of gallons per day into the ground or under your foundation without any visible evidence inside the home. The meter test is the way to confirm.
Who do I call if my water bill is high and I can't find the leak?
A licensed plumber with leak detection equipment (acoustic listening devices, thermal imaging, pressurized line testing) can locate a hidden leak without opening walls or slab until the location is confirmed. Call Honey Bear Plumbing at (865) 284-2424.
Will KUB (Knoxville Utilities Board) give me a credit for a leak?
KUB offers a Leak Adjustment credit for customers who have a confirmed leak repaired. You'll need documentation from a licensed plumber. Contact KUB customer service after the repair — this is a one-time adjustment, not automatic.
How much does leak detection cost?
Professional leak detection in Knoxville runs $300–$500 depending on the method and complexity. This fee is typically credited toward repair costs.
Leak Detection and Repair in Knoxville, TN
Honey Bear Plumbing locates and repairs water leaks throughout Greater Knoxville — from running toilets to slab leaks. If your bill spiked and you can't find why, we'll find it.
Call (865) 284-2424 or schedule online.