Guide, updated 2026-09-17
Seven signs of a hidden water leak in a valley home
The meter test, the warm floor, the sweating wall and the bill that moved for no reason. How to confirm a hidden leak before you call anyone. Sources linked.
- Sources linked at the foot of the page
- Written for Las Vegas and Clark County
The meter test settles it in twenty minutes and costs nothing. Turn off every fixture, appliance, ice maker and irrigation zone, note the meter reading, and check again twenty minutes later. If it moved with nothing running, water is escaping on your side of the meter.
Do the meter test first
This is the single most useful thing a homeowner can do before calling a plumber, and it is entirely observational.
Turn off every water fixture in the house. Then turn off the appliances that use water on their own schedule: the ice maker, the dishwasher, the washing machine, and any irrigation controller, which is the one people forget.
Find your water meter and note the reading, or watch the small leak indicator dial if yours has one. Wait twenty minutes without using any water. Read it again.
If the reading has moved, water is leaving the system with nothing running, which means a leak on your side of the meter. If it has not moved, your water use is genuine and a high bill has a different explanation.
The seven signs, in the order they usually get noticed
A gradual drop in pressure across the whole house belongs on the list too, though in older property it competes with corroded galvanised pipe as an explanation.
| Sign | What it points at |
|---|---|
| A water bill that stepped up and stayed up | A continuous leak rather than a one off event. The clearest signal on this list. |
| The sound of running water with everything off | A pressurised supply leak, often in a wall or under a slab. |
| A warm patch on a tile or concrete floor | A hot water line leaking under the slab. Highly specific and worth acting on. |
| A damp, stained or sweating wall or baseboard | Water travelling inside the wall. The source is frequently above or to one side of where it shows. |
| Paint bubbling, or drywall soft in one spot | Moisture behind the surface, usually ongoing rather than historic. |
| A musty smell in one room that will not clear | Persistent damp in a cavity. Often the earliest sign in a rarely used room. |
| A greener or wetter strip in the yard | An irrigation line or the main water service line. Frequently the cheapest of all of these to fix. |
Rule out irrigation before anything else
In this valley almost every property has an irrigation system, and irrigation leaks are both common and comparatively cheap to reach. They are also the most frequent cause of a mystery jump in water use.
If your system has its own shut off, close it and repeat the meter test. If the meter stops moving, the leak is in the irrigation rather than in the house, and that is good news for the repair bill.
Why locating is worth paying for
Finding a hidden leak and repairing one are different skills. Location uses meter isolation, acoustic listening, zone pressure testing and thermal imaging, and none of it breaks anything.
The alternative is exploratory demolition, which is expensive and frequently wrong, because water travels along framing and shows up somewhere other than its source. A located leak means one deliberate opening in the right place instead of a search.
What to do while you wait
If water is actively running and you cannot stop it at the fixture, close the main house shut off. In valley homes it is commonly in the garage near the water heater, on an exterior wall, or in a box at the front of the property near the street.
Photograph everything before you clean up. Dated photographs are the most useful thing you can hand an insurer later, and the moment passes quickly.
Keep people away from any water near outlets, a panel or an appliance, and do not stand in it.
When you do call someone, ask for their contractor licence number. Nevada licenses plumbing under classification C-1, Plumbing and Heating, through the Nevada State Contractors Board, and its register lets you check any licence in about a minute. Leak work often turns into repair work, so it is worth knowing before anyone opens a wall.
Sources for this guide
Every figure above comes from one of these, captured and checked on 17 September 2026. If a claim here has no source beside it, treat it as opinion.
Related services and guides
Guides worth reading
Ask us about your house
Reach Preferred Plumber Company
- Phone
- (725) 255-9011
- Licence
- Nevada State Contractors Board licence NV #0078989, C-1D Plumbing held by Preferred Plumbing LLC
- Service area
- Clark County, Nevada, including Las Vegas, Henderson, North Las Vegas, Summerlin, Paradise, Spring Valley, Enterprise, Sunrise Manor, Centennial Hills and Boulder City
We are a service area business. We come to you, so there is no counter to visit and no street address on this page. The number above is the fastest way in.
What to have ready
None of it is required. All of it makes the call shorter.
- Where you areThe address, and a cross street if the address is new or hard to find. Which end of the valley you are on decides who is closest.
- What is happening, in your own wordsNo plumbing vocabulary needed. "Water under the sink since this morning" is a better description than a guess at the cause.
- Whether water is running right nowThis is the question that changes everything else. If it is, say so first and we will talk you to the shutoff before anything else.
- What you have already triedPlunged it, reset the disposal, flipped the breaker, ran the softener through a regeneration. It saves repeating the steps that did not work.
- Whether you own or rentA landlord or an HOA sometimes has to authorise the work, and it is better to find that out on the phone than at the door.
Water pouring right now? Do not read the rest of this. Call (725) 255-9011 and shut off the supply while it rings.
Questions about this
How can I tell if I have a hidden water leak?
Run the meter test. Shut off every fixture, appliance, ice maker and irrigation zone, note the meter reading, and check again after twenty minutes. Movement with nothing running means a leak on your side of the meter. It costs nothing and it is more reliable than any single symptom.
What does a warm spot on the floor mean?
Usually a hot water line leaking under the slab. It is one of the most specific symptoms in residential plumbing, and combined with a moving meter it is a strong slab leak indication.
Could my high water bill just be irrigation?
Very often, yes, and it is the first thing worth ruling out because irrigation repairs are usually cheaper than anything inside the house. Shut the irrigation off and repeat the meter test.
Does a hidden leak damage the house quickly?
It depends where it is. Water inside a wall damages drywall and framing steadily. Water under a slab moves soil, and that is the version that turns a plumbing bill into a structural conversation. Neither is a same day emergency and neither improves with waiting.
Will my insurance cover a hidden leak?
That depends entirely on your policy and the cause, and no plumber can tell you what your policy covers. What helps is documentation: dated photographs, a written scope and located findings, which is what a proper leak detection visit produces.
Got a question this did not answer?
Describe what is happening at your property and you will get a straight answer about what it usually means.