What are expert tips for leak detection & prevention?

Your water meter is the best leak detection tool you own. Check it quarterly. Smart water leak detectors ($100-$300) sit on the main line and alert your phone to unusual water usage patterns. A $10 moisture meter from the hardware store can confirm suspected leaks behind walls without cutting drywall. Insurance companies are increasingly offering discounts for homes with automatic water shutoff systems.

What mistakes should I avoid with leak detection & prevention?

Ignoring a rising water bill -- it's the earliest sign of a hidden leak. Assuming a ceiling stain is from a one-time event. If it grows or returns after drying, the leak is active. Tightening a leaking fitting until it breaks. If a fitting leaks after snugging, the seal material needs replacement. Not knowing where the main water shutoff is. Find it now, before you need it in an emergency.

Leak Detection & Prevention

Maintenance Guide Easy to Intermediate 30-60 minutes for inspection $0 DIY inspection / $150-$500 for pro leak detection

Created by Ryan Pietrzak Illinois Licensed Plumber · In the plumbing industry since 2009

Updated February 20, 2026

Key Takeaway

The average household loses about 10,000 gallons of water per year to leaks. Most of those leaks are hidden -- behind walls, under slabs, in crawlspaces. By the time you see water damage, the leak has been running for weeks or months. Regular detection saves water, money, and the kind of structural damage that costs thousands to repair.

Overview

What to Know

The Water Meter Test

Turn off every water-using fixture and appliance in the house. Check the water meter -- if the dial is still moving or the flow indicator is spinning, you have a leak somewhere. Mark the meter reading, wait two hours without using any water, and check again. Any change means water is going somewhere it shouldn't.

Common Leak Locations

Under sinks (supply lines and drain connections), at toilet bases and supply valves, behind washing machines (supply hoses), water heater connections, outdoor hose bibs, and at any fitting where pipes were joined. Slab leaks happen underneath the foundation and show up as warm spots on the floor, sounds of running water when everything is off, or unexplained foundation cracks.

Visual and Audio Clues

Water stains on ceilings or walls, musty smells, mold or mildew in unusual places, warped flooring, peeling paint, and unexplained increases in your water bill. Listen for running water when no fixtures are on -- especially near walls where pipes run. A stethoscope or even a drinking glass held against the wall can amplify the sound.

Prevention Strategies

Replace rubber supply hoses (especially on washing machines) with braided stainless steel every 5 years. Check valve connections annually. Monitor your water bill for unexplained increases. Install a whole-house water leak detector that shuts off the main if it senses continuous flow. Maintain consistent thermostat settings in winter to prevent freeze-related leaks.

Pro Tips

Your water meter is the best leak detection tool you own. Check it quarterly.
Smart water leak detectors ($100-$300) sit on the main line and alert your phone to unusual water usage patterns.
A $10 moisture meter from the hardware store can confirm suspected leaks behind walls without cutting drywall.
Insurance companies are increasingly offering discounts for homes with automatic water shutoff systems.

Mistakes to Avoid

Ignoring a rising water bill -- it's the earliest sign of a hidden leak.
Assuming a ceiling stain is from a one-time event. If it grows or returns after drying, the leak is active.
Tightening a leaking fitting until it breaks. If a fitting leaks after snugging, the seal material needs replacement.
Not knowing where the main water shutoff is. Find it now, before you need it in an emergency.

When to Call a Pro

Slab leaks, leaks inside walls, and any leak you can hear but can't find require professional leak detection equipment (acoustic sensors, thermal cameras, or tracer gas). If your water bill has spiked and you can't find the source, a leak detection specialist can pinpoint it without tearing your house apart.

Bottom Line

Check your water meter quarterly, inspect visible connections twice a year, and pay attention to your water bill. Most leaks give warning signs long before they cause visible damage. Catching them early is the difference between a $5 fix and a $5,000 repair.