Emergency Plumbing → Diagnosis
How to tell if a pipe burst: every guide lists symptoms and none gives you a test. The signs of a burst pipe in the wall are settled by a thirty-minute meter procedure, and the EPA puts the window before mold begins at 24 to 48 hours.
How to tell if a pipe burst comes down to one measurement: with every fixture closed, a meter that keeps turning means water is escaping. The rest narrows down where.
Hidden leaks are the expensive ones. The EPA puts the mold window at 24 to 48 hours, and a cavity leak can run for weeks before anything shows.
The definitive test
Every tap, the dishwasher, the washing machine, the ice maker and any irrigation timer. Nothing may draw water for the next half hour.
Photograph the meter face, including the small low-flow triangle or star. That dial moves on flows too small to register on the main digits.
Leave the house alone. A short wait produces ambiguous results because thermal expansion can nudge the dial on its own.
Any movement means water is escaping on your side of the meter. No movement effectively rules out a burst supply line.
“What you could do is simply wipe down the floor where it’s wet and then come back a day later and see if that water is back there again.”
What are the signs of a burst pipe?
A water meter that turns with everything closed, pressure that has dropped at some fixtures but not others, running or hissing sounds with nothing switched on, and staining, bubbling paint or a musty smell downstream of the break.
Take them in that order. The meter is objective; the other three are corroborating evidence that helps locate it.
This decides who you call and what it costs. A supply line is pressurised all the time, so a supply leak runs whether you use water or not.
A drain leak only wets when something drains. A damp patch that appears after a shower and dries between uses is waste pipework.
The meter test only catches supply leaks, which is exactly why a negative meter test plus an intermittent damp patch points at the drain side.
Start at the fixture nearest the meter and work outward. Full pressure at the front and weak flow at the back places the break between them.
Check hot and cold separately. A pressure loss on the hot side only puts the break on the run out of the water heater, the classic slab-leak signature.
Stop mapping if water is near electrics
A ceiling that is holding water above light fittings, or any staining tracking toward the electrical panel, changes the priority. Cut that circuit from a dry position, or call the power company if you cannot reach the panel without standing in water. Diagnosis can wait; a live circuit in a wet ceiling cannot.
How to tell if a pipe burst is half the job. Where it burst is four jobs at four prices, and the search results treat them as one.
Underground cases raise ownership: anything on the street side of the meter is the utility’s. If water is inside, our guide to the first ten minutes after a pipe bursts covers the shut-off.
Building materials hide water. Insulation, subfloor and plaster absorb a large volume before any of it stains.
The EPA’s 24 to 48 hour drying window has usually passed several times over by the time a hidden leak shows, which is why concealed leaks end as mold remediation rather than pipe repair.
The water bill is often the first honest signal. A jump with no change in household use is worth a meter test the same day.
A service technician from Word of Advice TV describes the second trap: water appearing at an appliance often did not come from it. A wet patch marks where water arrived, not where it left.
Heat changes the leak rate: a crack opens when the system is hot and closes as it cools, so a leak that stops overnight has not sealed itself.
For early warning, Service Stars name whole-house leak detectors that sit at the main and close it when the flow looks like a leak. We have tested none, so that is a category rather than a recommendation.
Know the line
24/7 dispatch network
If the meter is moving and you cannot find the water, that is a leak-detection job. Send the symptoms and licensed, insured plumbers covering your area will contact you directly. No obligation.
Fire, a gas smell, or an injury? Leave the building and call 911 first, then your gas utility or power company. Use this form once you are safe.
At what temperature do pipes burst?
Water freezes below 32F, but the burst comes later and is caused by pressure, not by ice touching the pipe. An ice plug grows until the water trapped between it and a closed tap has nowhere to go, and the pipe splits at its weakest point.
This is why the split usually appears between the ice and the tap rather than at the frozen section itself, and why leaving a faucet open through a cold snap is such an effective preventative.
Exposure matters more than the outside temperature. An exterior-wall run, an uninsulated crawlspace or an unheated garage will freeze in conditions that leave the rest of the house untouched.
Indicative US ranges. Always get a written quote.
| Job | Typical range | Notes |
|---|---|---|
| Emergency trip fee | $75–$500 | Charged to attend and diagnose |
| Labor, standard hours | $100–$200 / hr | Includes locating the leak |
| Labor, after hours | up to $350 / hr | 1.5×–2× the base rate |
| Burst repair, accessible run | $150–$2,000 | Reported average near $500 |
| Burst repair, under slab | $500–$4,000+ | Locating and breaking concrete dominates |
| Main water line repair | from ~$225 | Reported where the homeowner digs the trench |
Detection is worth paying for when the meter says there is a leak and nothing says where. It costs a fraction of opening three walls to find the fourth was right.
Access, not the fitting, sets the price: an hour in an open basement, a day under a slab. Rate detail sits in our breakdown of the bill.
Emergency Services 24H is a referral service. Our plumbing section covers each fault, and the triage page settles whether tonight qualifies. We do not employ plumbers and we do not carry out detection or repair work.
Your request routes to licensed, insured contractors nearby. The rate tables exist so you can judge the quote rather than take it on trust.
Straight answers
The questions homeowners actually search for on this problem, answered in plain language.
Browse all guidesA drop in pressure, a hissing or running sound with every tap closed, a warm or cold patch on the wall, staining or bubbling paint, and a water meter that keeps moving. Any one is suggestive; the meter test settles it.
Yes, and it is the most effective thing you can do. A pipe splits because the ice plug pressurises water trapped against a closed tap; a dripping faucet gives it somewhere to go.
Close every tap and appliance, then watch the meter. A low-flow indicator still turning after thirty minutes means water is escaping on your side. Add uneven pressure or a hiss behind drywall and you have a burst supply line.
Easily, inside a wall, above a ceiling or under a slab. Cavity insulation absorbs a surprising volume before anything shows, and the first signal is often the water bill.
Pipes freezing below 32F is not what bursts them; pressure is. As the plug grows, water trapped against a closed tap has nowhere to go. Keep pipes on an outside wall insulated.
Banging when a tap closes, a hiss with nothing running, or a gurgle then a trickle at a fixture that ran full. A tap slowing in cold weather means an ice plug upstream.
Accessible repairs run $150 to $2,000, averaging near $500. Under a slab it is $500 to $4,000, because locating and breaking through dominates the labor. Add a $75 to $500 trip fee.
Slab leaks show as a warm patch over a hot line and running water underfoot with everything closed. Wall leaks stain along framing and surface below the break.
Independent, publicly published sources, quoted with attribution and linked in full. None is affiliated with Emergency Services 24H, reviewed this page, or works in the referral network.
Reviewed on . If a figure here no longer matches its source, that is a bug, so tell us and we will correct it.
24/7 dispatch network
Tell us what has failed and how soon you need someone. We route your request to licensed, insured contractors covering your area, and they contact you directly.
Fire, a gas smell, or an injury? Leave the building and call 911 first, then your gas utility or power company. Use this form once you are safe.