08/20/2026
Check out our new blog post on leak detection in Los Angeles:
Hidden water leaks can be a sneaky culprit costing you thousands
A water leak is not always as obvious as a burst pipe or water flooding across the floor. In many cases, leaks begin slowly and remain hidden behind walls, beneath floors, under sinks, or underground. By the time visible damage appears, the leak may have already caused significant water damage or wasted a substantial amount of water.
For homeowners and businesses in Los Angeles and surrounding communities—including Pasadena, Glendale, Burbank, Hollywood, and throughout Los Angeles County—knowing the warning signs of a water leak can help you address a plumbing problem before it becomes more expensive and disruptive.
Kessler Plumbing & Heating Inc provides professional leak detection and leak repair for residential and commercial properties, helping customers identify the source of hidden leaks and make the necessary repairs.
We're fully licensed, bonded, and insured. And we've been in business for more than 100 years with thousands of satisfied customers.
What Are the Signs of a Hidden Water Leak?
Some plumbing leaks are easy to spot. Others can continue for weeks or months without being immediately noticeable. Paying attention to changes around your property can help you identify a potential problem.
Common signs of a water leak include:
An Unexplained Increase in Your Water Bill
If your water usage habits have not changed but your water bill suddenly increases, a hidden leak may be wasting water. Even a relatively small leak can add up over time.
The Sound of Running or Dripping Water
Do you hear water running, dripping, or moving through your plumbing when faucets and appliances are turned off? This can sometimes indicate a leak in a water line.
Damp Spots or Water Stains
Water stains on ceilings, walls, or floors should never be ignored. Discoloration, bubbling paint, peeling wallpaper, or unexplained dampness may indicate that water is leaking behind the surface.
Musty or Unusual Odors
Persistent moisture can create a damp environment and may eventually contribute to mold growth. A musty smell near a wall, cabinet, bathroom, or other area of the property may be a sign that hidden moisture is present.
Warm or Damp Areas on the Floor
An unexplained warm spot on the floor may indicate a problem with a hot water line beneath the slab or flooring. Damp carpeting, warped flooring, or soft areas can also indicate that water is leaking where it should not be.
Mold or Mildew Appearing in Unusual Places
Bathrooms naturally experience moisture, but mold or mildew appearing repeatedly in areas that should remain dry can be a warning sign of a plumbing leak. Hidden leaks can provide the moisture necessary for mold to grow.
Low Water Pressure
A sudden or unexplained decrease in water pressure can sometimes be related to a damaged or leaking water line. Other plumbing issues can also cause low pressure, so a professional inspection may be necessary to determine the source.
Puddles or Wet Areas Outside
Water collecting in your yard when irrigation is not running may indicate an underground water leak. This is especially important to investigate if the affected pipe supplies an irrigation system, pool, outdoor fixture, or another water source.
What Causes Water Leaks?
Water leaks can occur for many reasons. Plumbing systems experience years of use, changes in water pressure, temperature fluctuations, ground movement, and normal wear and tear.
Some common causes include:
Aging or deteriorating pipes
Corrosion
Loose or damaged plumbing connections
Worn seals, washers, or valves
High water pressure
Damaged supply lines
Cracked drain pipes
Shifting soil or ground movement
Tree root intrusion affecting underground plumbing
Improper installation or previous repairs
Freezing temperatures in areas where pipes are exposed
In an older property, aging plumbing components can become more vulnerable to leaks. Even newer plumbing systems can develop problems when fittings fail, pipes are damaged, or excessive pressure places stress on the system.
What Are the Most Common Sources of Water Leaks?
Leaks can develop almost anywhere water travels through a property. Some of the most common sources include:
Toilets
A toilet may leak from the supply line, shutoff valve, tank, wax ring, or other plumbing components. Some toilet leaks are obvious, while others can remain hidden behind or underneath the fixture.
Faucets and Sinks
A dripping faucet is easy to notice, but leaks under the sink can go undetected inside a cabinet. Loose drain connections, damaged P-traps, worn seals, and deteriorating supply lines can all allow water to escape.
Showers and Bathtubs
Shower valves, drain assemblies, pipes, and surrounding plumbing connections can all develop leaks. Water damage may occur behind walls or beneath flooring before the problem becomes visible.
Water Supply Lines
Flexible supply lines connected to toilets, faucets, appliances, and other fixtures can wear out or become damaged. A slow leak may begin with only a few drops of water but continue to cause moisture damage over time.
Water Heaters
Leaks around a water heater may result from fittings, valves, supply lines, or the tank itself. Because water heaters hold a significant amount of water, problems should be addressed promptly. Unforeseen floods can wreak havoc on a home and cost a large sum of money to repair if they burst or flood. We are water heater experts for more than 100 years!
Appliances
Dishwashers, refrigerators, washing machines, and other appliances may have water supply lines or drain connections that can leak.
Underground Water Lines
Leaks beneath the ground can be especially difficult to identify because the damaged pipe is not visible. These leaks may affect irrigation systems, swimming pools, water supply lines, or other underground plumbing.
Professional leak detection can help identify the source before excavation or repairs begin. Depending on the location and type of leak, the repair may involve accessing the damaged pipe, removing the affected section, and completing a thorough repair.
What Harm Can a Water Leak Cause?
The longer a leak continues, the greater the potential for damage. What begins as a slow drip can eventually become a much more costly plumbing problem.
Water leaks may cause:
Damage to walls, ceilings, flooring, and cabinets
Warped or deteriorating building materials
Mold and mildew growth where persistent moisture is present
Damage to personal belongings or business property
Higher water bills and unnecessary water waste
Damage to landscaping or soil erosion from underground leaks
Structural concerns if significant water damage is left unaddressed
Disruption to your home or business during more extensive repairs
A small leak does not always remain small. Addressing the source early can often help prevent additional damage and reduce the scope of repairs.
When Is It Time to Call a Plumber?
It is a good idea to call a plumber when you notice signs of a possible leak and cannot identify or safely repair the source yourself. Prompt professional attention is particularly important when water is actively leaking, damage is spreading, or the source is hidden behind a wall, beneath a floor, or underground.
You should consider calling a plumber if:
Your water bill has increased unexpectedly
You see unexplained water stains or damp areas
You smell persistent musty odors
You hear water running when everything is turned off
Water pressure suddenly changes
You discover water beneath a sink, toilet, appliance, or water heater
You see unexplained puddles or wet areas in your yard
You suspect a slab or underground leak
You have recurring leaks or repeated water damage
The goal is not simply to stop the visible water. A proper repair should identify the actual source of the leak and address the underlying plumbing problem. Call us today and request a free estimate or home inspection!
Professional Leak Detection and Leak Repair in Los Angeles
Hidden leaks can be stressful because the source is not always obvious. Choosing an experienced, trustworthy plumber can make an important difference when your property, water supply, and potential repair costs are involved.
Kessler Plumbing & Heating Inc. provides leak detection and leak repair for homes and businesses throughout Los Angeles and surrounding communities, including Pasadena, Glendale, Burbank, Hollywood, and other areas of Los Angeles County.
As a locally owned small business that has served the community for more than 100 years, Kessler Plumbing & Heating Inc. understands the importance of careful workmanship, clear communication, and fair, honest pricing. The company is licensed, bonded, and insured and can help identify and repair many types of plumbing leaks, from visible fixture leaks to hidden and underground water leaks.
If you suspect a water leak, calling us sooner rather than later can help protect your property, conserve water, and prevent a small plumbing issue from becoming a much larger problem.
Call now to connect with business.
