Signs a leak is active now
Pooling water, a ceiling stain that is growing, the sound of running water when no fixture is on, a floor that feels warm or damp, and a meter that moves with all taps closed are all active leak signs. Treat them as urgent, because hidden water damages framing, drywall and flooring and feeds mold.
Shut off the main water valve if you can reach it. If the leak stops, the problem is on the house side. Then call, and tell the dispatcher what you saw and what you shut off.
A five-minute meter check before we arrive
The City of Mountain View publishes steps for checking the meter. The meter is usually in a box near the curb. Turn off all water-using fixtures, including the washer and irrigation. Find the small triangle or asterisk near the center of the dial. If it turns for a couple of minutes with no water in use, you have a leak.
Then close the house valve, which is typically near a hose bib, and check again. If the indicator still turns, the leak is between the house and the meter. If it stops, the leak is inside the house or in the irrigation system.
How a plumber finds a hidden leak
- Isolate the system. Fixtures, zones and supply branches are closed off one at a time to narrow which section loses water.
- Pressure test. Gauges on isolated lines show whether pressure holds. A drop means a leak in that section.
- Listen and scan. Acoustic equipment hears the sound of leaking water in the pipe, and thermal imaging shows temperature differences in walls and floors.
- Mark the spot. The plumber marks the location so only a small opening is needed. Then comes the repair or a quote for it.
Meter moving with everything off? Call now.
Call (650) 860-1670| Location | What you notice | Related service |
|---|---|---|
| Under the slab | Warm floor spots, high bill, sound of water | Slab leak repair |
| Between meter and house | Meter moves, house valve closed, yard stays wet | Water line repair |
| Inside a wall | Stain, musty smell, peeling paint | Burst pipe repair |
| Toilet or fixture | Meter moves slowly, fixture is quiet | Toilet repair |
| Irrigation | Wet lawn spots, meter moves outdoors | Call for diagnosis |
What affects leak detection cost
- Size of the property. More pipe means more testing time.
- Type of leak. A slow drip in a fixture is quicker than a leak under concrete.
- Equipment used. Acoustic and thermal tools take setup and skill.
- Access. Finished floors and walls take care to avoid damage.
- Repair afterward. Finding the leak is one price and fixing it is another.
Some insurers cover the cost of finding a leak that caused covered damage. Ask yours before the visit. The plumber states the price before testing starts.
What the City offers customers
The City's water conservation pages say you can request a free do-it-yourself leak detection kit by calling 408-630-2554, and that fixing a leak may qualify you for a one-time water bill reduction. Both are worth asking about. A plumber's invoice showing the leak and the repair is usually what such a reduction requires, so keep it.
Many mid-century homes in Monta Loma sit on slabs, and some Eichler homes have heating pipe in the floor. A leak in a pipe cast into a slab behaves differently from a wall leak, and a warm floor spot is the clue.
Repairs that follow a leak search, such as replacing a section of supply pipe, are made to the California Plumbing Code, and the plumber who finds the leak can repair it to that standard.
Leak Detection questions
Is emergency leak detection available at night in Mountain View?
Yes. Call (650) 860-1670 at any hour. A licensed plumber is dispatched to locate the leak, and you can shut the main valve in the meantime.
How can I tell if I have a hidden leak?
Check your meter with everything off. If the indicator on the dial turns, water is moving through the system. Rising bills with no change in habits are the other signal.
Will you have to cut into my walls?
Only where the leak is. Acoustic and thermal tools narrow the spot so the opening is small.
What if the leak is under the slab?
That is a slab leak. Options include rerouting the pipe, a spot repair through the slab or repiping. The plumber explains each.
Does the City help with a high bill from a leak?
The City's conservation page says a one-time bill reduction may be available after a repair. Keep the plumber's invoice.