How to Prevent Frozen Pipes in Your New Hampshire Home

New Hampshire winters are no joke. With temperatures regularly dropping below -10°F in many parts of the state, frozen pipes are a real and expensive risk for homeowners who aren't prepared. In this guide, our licensed NH plumbers share everything you need to know to protect your home's plumbing through even the harshest Granite State winters.

Why Frozen Pipes Are Especially Dangerous in New Hampshire

Water expands approximately 9% when it freezes. In a closed pipe, this expansion creates enormous pressure — up to 2,000 PSI — that can split copper, crack PVC, and burst PEX pipes regardless of their quality. A single burst pipe can release hundreds of gallons of water per hour into your home before you even realize something is wrong.

In New Hampshire, the combination of extreme cold, older housing stock, and unheated spaces like crawl spaces and attached garages makes frozen pipes one of the most common plumbing emergencies we respond to every winter. The average water damage claim from a burst frozen pipe in NH runs between $5,000 and $20,000.

Which Pipes Are Most Vulnerable to Freezing in NH Homes?

Not all pipes are equally at risk. Understanding which pipes are most vulnerable helps you prioritize your prevention efforts:

• Exterior wall pipes: Pipes running through exterior walls with insufficient insulation are extremely vulnerable when NH temperatures plunge.
• Crawl space pipes: Many older NH homes have supply lines running through unheated crawl spaces — these are high-risk.
• Garage pipes: Water supply lines to utility sinks in unheated garages freeze regularly in NH winters.
• Attic pipes: Any plumbing that runs through unheated attic spaces is at significant risk.
• Outdoor hose bibs: These must be properly winterized each fall without exception in New Hampshire.
• Pipes near windows or uninsulated areas: Cold drafts can create localized freezing even in heated spaces.

10 Ways to Prevent Frozen Pipes in New Hampshire

1. Insulate Exposed Pipes Before Winter

Foam pipe insulation from a hardware store is inexpensive and highly effective. Wrap any pipes in unheated areas — crawl spaces, attics, garages, and exterior walls — with pipe insulation sleeves before temperatures drop. For pipes in extreme cold zones, use heat tape combined with foam insulation.

2. Seal Air Leaks Near Pipes

Cold air drafts are often the culprit for frozen pipes even in heated spaces. Inspect areas where pipes pass through walls or floors and seal any gaps with caulk, expanding foam, or weather stripping. Even a small hole can allow enough cold air to freeze a pipe during an NH cold snap.

3. Maintain Minimum Interior Temperature

Never let your NH home drop below 55°F, even when you're away. During extended cold periods when temperatures drop well below zero, keep your thermostat at 60°F or higher. The cost of extra heating fuel is far less than the cost of a burst pipe and resulting water damage.

4. Open Cabinet Doors Under Sinks

On extremely cold nights, open cabinet doors under sinks on exterior walls. This allows warm air from your living space to circulate around the pipes, significantly reducing freeze risk.

5. Let Faucets Drip During Extreme Cold

When NH temperatures are forecast to drop below 0°F, let faucets served by vulnerable pipes drip slowly — both hot and cold. Moving water requires much more energy to freeze, and the slight pressure relief can prevent a burst even if the pipe does start to freeze.

6. Properly Winterize Outdoor Hose Bibs

Every fall before the first freeze, shut off the interior valve supplying your hose bibs, then open the exterior bib to drain the line. Install foam hose bib covers as an additional layer of protection. This simple step prevents one of the most common causes of frozen pipe damage in NH homes.

7. Disconnect Garden Hoses

This seems obvious but is frequently overlooked. A garden hose left connected traps water in the bib and supply line, regardless of whether you've shut off the interior valve. Always disconnect hoses before the first hard freeze in New Hampshire.

8. Add Pipe Heat Tape to High-Risk Areas

For pipes in particularly vulnerable locations — unheated crawl spaces or pipes on exterior walls with inadequate insulation — self-regulating heat tape provides reliable protection. These plugged-in cables automatically adjust their heat output based on ambient temperature.

9. Keep Garage Doors Closed

If you have water supply lines running through your attached garage, keep the garage door closed during cold snaps. Even a short period with the door open during extreme cold can be enough to freeze exposed pipes.

10. Know Where Your Main Water Shutoff Is Located

This is your emergency preparedness step. Before winter, locate your main water shutoff valve and make sure everyone in your household knows where it is and how to turn it off. In a pipe burst emergency, shutting off water immediately is the single most important action to limit damage.

What to Do If Your Pipes Freeze in New Hampshire

Despite your best prevention efforts, pipes can still freeze during an extreme NH cold snap. Here's what to do:

1. Turn on the faucet: Open the faucet the frozen pipe serves. As you thaw the pipe, running water will help melt ice and relieve pressure.
2. Locate the frozen section: Look for frost on exposed pipes or areas where you have less water flow than usual.
3. Apply heat carefully: Use a hair dryer, heat lamp, or electric heating pad starting from the faucet end. Never use an open flame — this is a fire hazard and can damage pipes.
4. Check for cracks: After thawing, inspect the pipe carefully for cracks or splits. Even a small crack can release significant water.
5. Call a plumber if you can't locate or access the frozen pipe: Pipes inside walls or under slabs require professional equipment to thaw safely.

When to Call an Emergency Plumber in New Hampshire

Call (603) 555-0100 immediately if:

• You can't locate the frozen section of pipe
• You attempt to thaw the pipe but get no water flow restoration
• You hear a loud pop or see water leaking after a freeze
• You have multiple frozen pipes
• Pipes are inside walls or under flooring where you can't access them
• You see any evidence of a burst pipe (water staining, wet drywall, flooding)

Our licensed NH plumbers respond to frozen and burst pipe emergencies 24 hours a day, 7 days a week. We serve all of New Hampshire including Manchester, Nashua, Concord, Dover, Portsmouth, Keene, and every community in between.

Frozen Pipe Prevention Services in New Hampshire

Don't wait for a disaster. Our licensed NH plumbers offer pre-winter plumbing inspections that identify vulnerable pipes, recommend insulation upgrades, install heat tape, and ensure your plumbing is fully prepared for another New Hampshire winter. Call (603) 555-0100 to schedule your pre-winter plumbing inspection today.