A water service line leak is urgent when water is surfacing in the yard, when pressure drops suddenly, or when the meter keeps running with every fixture off. Our 24/7 line takes those calls at night and on weekends, and a licensed plumber can come the same day when the schedule allows.
While you wait, close the main valve inside the house. If the yard is flooding, note where the water appears and keep children away from soft ground. Do not dig near utility lines.
Meter still running? High water bill?
Many calls start with a symptom and not a diagnosis. The bill climbed. The meter spins when nothing is on. A wet patch appears where the grass is greener. Each of these can point to a leak in the service line.
- Turn everything offStop all taps, appliances and irrigation.
- Read the meterNote the leak indicator or low-flow dial, wait 15 minutes and read it again.
- Close the mainIf the meter stops, the leak is inside the house. If it keeps running, the leak is on the service line side.
- Call usTell the dispatcher what you saw so we can bring the right tools.
Homes on private wells have no meter, so a pump that cycles constantly or a pressure tank that never holds is the clue.
A broken service line is an emergency: how we find the leak
When the line breaks, water can surface in the yard or flood a basement wall within minutes. Close the main shutoff, then call the 24/7 line so a plumber can be scheduled the same day when available.
A buried line can leak without any visible sign. We use pressure tests, acoustic listening gear and line tracers to find the spot. For plastic pipe, tracing needs a tone signal. Once the point is marked, we dig only where needed. Our leak detection page explains these tools in more detail.
Irrigation lines and meter-box fittings can also leak. We check them before assuming the main line has failed.
Low water pressure
| Symptom | Possible cause | What we check |
|---|---|---|
| Weak flow at every fixture | Leak or restriction in the service line | Pressure at the main, the meter and the shutoff |
| Low flow at one fixture | Clogged aerator, cartridge or supply valve | That fixture and its supply |
| Low hot water only | Scale in the heater or hot lines | The heater and the pipes |
| Pressure swings | Failing pressure reducing valve | The valve, set to a safe pressure |
We trace the cause before we replace anything. A pressure reducing valve that has failed can push pressure up and burst fixtures, so we test it.
Repair or replace the line?
A short leak in good pipe can be repaired with a new section and proper fittings. Old galvanized, lead or failing plastic lines are better replaced. We tell you which case you have after we uncover the pipe.
Trenchless methods may be possible depending on depth and obstacles, though not every line suits them. When the line runs under a driveway, the conversation takes longer and we cover the choices clearly.
Town water, private wells and water main work
Whether your line comes from a town system or a private well changes who owns which part of it. Ask your utility or Londonderry Public Works at 603-432-1100, extension 460, where the town's responsibility ends and yours begins.
Town news lists water main extension projects for 2026 on Old Nashua Road, Old Derry Road and South Road. If your street is affected, expect pressure changes and delays and tell us about them.
Many Londonderry homes use private wells, and wells in this region have shown PFAS contamination linked to the former Saint-Gobain plant in Merrimack. Test your well water, and ask the state environmental agency about testing and treatment programs. A line repair is a good moment to check your water.
What service line repair costs
We quote before work begins. The price depends on:
- Line length, depth and pipe material.
- Digging conditions, such as ledge, driveways or landscaping.
- Whether we repair a section or replace the line.
- Fittings, shutoff valves and any pressure reducing valve.
- After-hours dispatch.
Insurance rarely covers the line itself but may cover resulting damage. Ask your agent. For your number, call (603) 815-9179.
Where we repair service lines
We serve all of Londonderry and nearby towns including Windham, Litchfield and Manchester. If a line failure has caused a pipe to burst indoors, see burst pipe repair.
A new service line is sized and buried to the International Plumbing Code (IPC) and the water utility's own rules.
Questions we hear in Londonderry
Yes. Call (603) 815-9179 any time. We take night, weekend and holiday calls and dispatch the same day when the schedule allows.
Turn everything off, read the meter, close the main valve and read it again. If the meter keeps running with the main closed, the leak is on the service side.
A leak, a failed pressure valve, a stuck shutoff or a clogged line can all do it. We test pressure at several points to find which.
It varies. Ask your utility or Londonderry Public Works at 603-432-1100, extension 460.
Often, if the pipe is sound beyond the break. Old or corroded lines are usually better replaced.
Yes. We repair the water line between the well and the house and check the pressure tank.