Frozen and Burst Pipe Repair in Portsmouth, NH

Frozen and Burst Water Pipes: First Priorities

If water is escaping, close the main water shutoff first. Then deal with electricity, people and belongings, in that order.

A frozen pipe that is not leaking is a different situation. You usually have more time, but the pipe can split once the ice thaws.

Your first priorities, in order:

• Stop escaping water at the main shutoff, if you can reach it safely.
• Keep everyone out of standing water near outlets, appliances or a panel.
• Move valuables and electronics away from dripping ceilings.
• Call for professional help once the immediate risk is controlled.
• Take photos before cleanup if you may file an insurance claim.

Signs of a Frozen Pipe Before It Bursts

The clearest early sign is a faucet that gives a trickle or nothing during a cold snap, while other fixtures still flow.

Other clues help confirm a freeze rather than a different fault:

• Frost or condensation on a visible pipe in a cold basement or crawl space.
• Reduced flow at fixtures on exterior walls only.
• A toilet that refills very slowly after flushing.
• Strange gurgling or clanking when a nearby tap is opened.
• An unusually cold section of wall or cabinet near the affected fixture.

None of these proves a freeze on its own. A failed valve, a clogged aerator or a well-system problem can also reduce flow.

Warning Signs of an Active Pipe Break

An active break usually announces itself with water where it should not be. Treat any of these as urgent:

• Water dripping from a ceiling, light fixture or cabinet base.
• A hissing or spraying sound inside a wall or under a floor.
• A sudden pressure drop across the whole building.
• Water spreading across a basement floor during or after a cold spell.
• A water meter that keeps moving with every fixture turned off.

A split often stays hidden while the pipe is frozen. Water may only appear hours later, when the ice softens and pressure returns.

Where to Find and Use a Water Shutoff

Most homes on public water have a main shutoff valve near where the supply pipe enters the building. That is often in a basement, utility room or crawl space, close to the meter.

Turn a round wheel handle clockwise until it stops. A lever handle is usually closed when it sits crosswise to the pipe.

Do not operate valves at the street or curb. In Portsmouth, the City describes the line from the water main to the shutoff valve as the utility’s portion, so street-side valves are for the Water Division.

Source: City of Portsmouth — Water Service Line Inventory, reviewed October 2026.

If the indoor valve will not turn, do not force it with a long bar. Call the City Water Division at (603) 427-1530 for utility-side help, and tell the plumbing provider the valve is stuck.

Water Near Electricity: Safety First

Do not walk into standing water if outlets, cords, appliances or the electrical panel may be wet. Water and household current are a dangerous combination.

If you can reach the panel from a dry location, you may switch off affected circuits. If reaching it means stepping through water, stay out and call your electric utility or 911.

Watch for these hazards in particular:

• Water dripping into or around a ceiling light fixture.
• A submerged extension cord, space heater or dehumidifier.
• Sparking, buzzing or a burning smell.
• A wet electrical panel or meter base.

A plumber repairs pipes. Wet wiring, fixtures or panels need an electrician to inspect them before power is restored.

Do Not Use Flames to Thaw Pipes

Never use a torch, lighter, propane heater or any open flame on a frozen pipe. Flames start house fires, especially inside walls and near old framing.

Also avoid these common shortcuts:

• Heat guns aimed at pipes inside cabinets or wall cavities.
• Charcoal or fuel-burning heaters indoors, which create carbon monoxide risk.
• Electric heaters set up in standing water or on wet floors.
• Boiling water poured directly onto pipes or fittings.

If you choose to warm the room around an exposed, accessible pipe, keep the heat source at a safe distance and supervised. If the frozen section is hidden, leave thawing to a professional.

Why Lines Freeze in Portsmouth Winters

Pipes freeze when cold air reaches water that is not moving. In Seacoast winters, that usually means plumbing near the building’s outer shell.

Common contributors include:

• Supply lines inside exterior walls with little insulation.
• Unheated crawl spaces, garages and enclosed porches.
• Drafts from foundation gaps, sill plates or dryer vents.
• Outdoor faucets that were not drained before winter.
• Long periods with the heat turned down or off.

Wind matters as much as the thermometer. A steady draft on one pipe can freeze it on a night that seems only moderately cold.

The City of Portsmouth publishes winter guidance on property-owner responsibilities and freeze prevention. See Protect Your Pipes This Winter, published January 2018.

How Freezing Causes a Split After Thawing

Water expands as it freezes. The ice plug traps water between itself and a closed faucet, and pressure builds in that trapped section.

That pressure is what splits the pipe or forces a fitting apart. The break often sits away from the ice itself.

While frozen, the crack is sealed by ice. Once it thaws, full supply pressure pushes through the opening.

This is why a “fixed” frozen pipe can flood a room an hour later. Stay close by while any pipe thaws, and know where the shutoff is first.

Indoor Supply Lines Versus Exterior Lines

Indoor supply lines are pipes inside the heated envelope, even if they run along cold walls. Exterior lines include outdoor faucets, garage feeds and buried pipes.

The difference changes the response:

A buried line that freezes is less common, but it is possible. If the whole building has no water, check with the Water Division as well as a plumber.

What to Do When One Fixture Stops Flowing

If only one tap has stopped during a cold snap, a frozen section near that fixture is a reasonable suspicion. Act calmly and step by step:

Do not leave thawing pipes unattended. Watch for drips as flow returns.

What to Do When Water Begins Escaping

Once water is visibly escaping, shut off the main supply immediately. Then open a cold faucet at the lowest point to drain remaining pressure.

Next, contain the damage:

• Ask the provider whether your water heater should be turned off while supply is shut.
• Move furniture, rugs and stored boxes out of the wet area.
• Use towels and buckets for drips, but stay clear of electrical hazards.
• Photograph the break, water level and damaged items.
• Note when the leak started and when you closed the valve.

Call (844) 442-1700 once the water is off to discuss repair and confirm timing.

(844) 442-1700

When a Professional Repair Is Needed

A professional repair is needed whenever a pipe has split, a fitting has separated, or a frozen section sits inside a wall, ceiling or floor.

You should also ask for help when:

• The main shutoff will not close or still leaks.
• Water reached ceilings, light fixtures or the electrical panel.
• Several fixtures stopped working at once.
• The frozen pipe feeds a boiler, water heater or sprinkler system.
• You cannot tell where the water is coming from.

If water is escaping but you cannot find it, the source may be concealed. A concealed pipe leak repair normally starts with locating that section first.

Frozen Pipe Versus Clogged Fixture: Clues

Cold weather makes every slow faucet look frozen. Some simple clues help separate the two before you call.

Drain backups are a separate issue. Slow sinks or toilets that will not empty point to drain lines, not frozen supply pipes.

Repairing a Split or Damaged Section

Most burst-pipe repairs replace the damaged length rather than patching the crack. The provider assesses the material, joint type and how far the damage extends.

A repair visit commonly includes:

• Confirming the water is off and the line is drained.
• Inspecting the pipe on both sides of the visible split.
• Cutting out the damaged section and fitting a matching replacement.
• Checking nearby fittings that froze alongside it.
• Restoring pressure slowly and watching for new drips.

Freeze damage can affect more than one spot. A careful repair checks the whole exposed run, not just the obvious split. For non-freeze leaks, see water leak repair.

Comparing Thawing, Repair, and Replacement

These are three different jobs, and the right one depends on what the freeze actually did.

Ask the provider to explain why one option fits your pipe better than another. A good answer refers to what they observed, not to a standard package.

What Work May Be Needed Behind Walls

When the frozen section is inside a wall or ceiling, access usually means opening a section of the surface.

The size of the opening depends on where the break is and how much pipe must be replaced. Ask before any cutting starts.

Typical questions include:

• How large will the access opening be, and where?
• Will the provider patch the opening, or is that separate work?
• Is there insulation inside the cavity that needs replacing?
• Should the pipe be moved away from the exterior wall?

Plumbing providers often do not finish drywall, plaster or paint. Plan on the possibility of a separate trade for surface restoration.

Insulation, Air Sealing, and Exposure

Repairing the pipe without fixing the cold exposure invites the same freeze next winter. Ask what caused the freeze at this location.

Measures that are often discussed after a repair:

• Pipe insulation sleeves on accessible runs in cold spaces.
• Sealing drafts at sill plates, rim joists and pipe penetrations.
• Insulating crawl-space walls rather than only the pipes.
• Rerouting a supply line away from a cold exterior wall.
• Adding an interior shutoff and drain for an outdoor faucet.

Do not block combustion air openings for furnaces, boilers or water heaters. Air sealing near fuel-burning equipment needs professional judgment.

For a full seasonal plan, see the guide on how to prevent frozen pipes.

Seasonal Homes and Unoccupied Buildings

Seasonal homes and vacant properties carry extra risk, because a break can run for days before anyone notices.

If a property will sit empty in winter, owners commonly consider:

• Closing the main shutoff before leaving.
• Keeping heat on at a steady, safe setting.
• Asking someone to check the building after each cold snap.
• Asking a plumber whether draining the system makes sense.
• Keeping the plumber’s and Water Division’s numbers posted near the valve.

Some insurance policies set conditions for unoccupied buildings. Check your own policy wording rather than assuming coverage.

What Affects Emergency Repair Scope

The scope of a burst-pipe repair depends far more on location and damage than on the size of the crack.

Factors that commonly change the job:

• Whether the pipe is exposed, in a wall, or under a floor.
• The pipe material and whether old and new materials must join.
• How many sections froze and split.
• Access around cabinets, tile, finished ceilings or tight crawl spaces.
• Whether the main shutoff works or must be replaced first.
• Whether water damage requires drying before closing walls.

Pricing is set by the provider. Ask how the visit and repair are charged before work starts.

What to Ask About Actual Service Hours

Do not assume any plumber offers round-the-clock service. Ask directly when you call.

Useful questions include:

• Is someone available today, or what is the next opening?
• Do after-hours or weekend visits cost more?
• Will the first visit stop the leak, repair it, or both?
• What should I do with the water shut off until you arrive?

Call (844) 442-1700 and ask these questions. Availability for your address and time is confirmed by the provider on the call.

(844) 442-1700

If you are outside Portsmouth, check our service areas before calling.

After-Repair Checks and Prevention

After the repair, keep watching the area for a few days. A second freeze-damaged fitting sometimes shows up only after pressure is restored.

Check these points:

• No drips at the new joints after a full day of normal use.
• Normal flow and pressure at every fixture.
• The water meter stays still when nothing is running.
• Ceiling stains and wet drywall are drying, not spreading.
• The cause of the freeze has been addressed or scheduled.

If moisture keeps appearing near the repair, call back. Ongoing dampness may mean another leak or wet materials that need drying.