How to Prevent Frozen Pipes in Northern Virginia

How to prevent frozen pipes guide graphic

Northern Virginia winters swing between mild days and sudden hard freezes. Those cold snaps are when we see burst pipes in McLean homes, usually in pipes along outside walls, in garages and crawl spaces, and at hose bibs. A few minutes of preparation can prevent a flooded basement. If a pipe has already burst, close the main water valve and call our emergency plumber in McLean right away.

Which pipes are most likely to freeze?

Pipes freeze where cold air reaches them and warm air does not. Red Cross guidance, as reported by CBS News, points to pipes against exterior walls and where water enters the home through the foundation. In local homes, the usual trouble spots are:

Location	Why it freezes
Outdoor hose bibs and their supply lines	Exposed to outside air
Kitchen and bath sinks on outside walls	Little insulation in the wall cavity
Crawl spaces	Unheated, often drafty
Garages	Doors open, no heat
Where the water line enters the basement	Cold foundation wall
Irrigation and pool lines	Outside and often above the frost line
Pipes in attics or over garages	Unheated spaces

How to prevent frozen pipes before winter

Do these in fall, before the first hard freeze.

Shut off and drain hose bibs. Close the inside valve that feeds each outdoor faucet, then open the outside faucet to drain it. Disconnect hoses.
Blow out irrigation. Have the system winterized so water does not sit in lines and backflow parts.
Insulate exposed pipes. Foam sleeves on hot and cold pipes in crawl spaces, garages and unfinished basements help.
Seal drafts. Close gaps where cold air reaches pipes, such as around the water line entry and dryer vents.
Find your main shutoff valve. Test it so it turns when you need it.
Check the sump pump discharge. A frozen outdoor discharge line can back water into the basement.

What should I do during a cold snap?

When the forecast calls for a hard freeze, take these steps:

Keep the heat steady. Set the thermostat to the same temperature day and night.
Open cabinet doors under sinks on outside walls so warm room air reaches the pipes.
Let faucets drip. A slow trickle from faucets fed by exposed pipes keeps water moving.
Keep the garage door closed if water lines run through the garage.
Leave the heat on when you travel. A common minimum is 55°F. For longer trips, consider shutting off the main valve and draining the lines.

How do I know if a pipe is frozen?

If you turn on a faucet and only a trickle comes out, suspect a frozen pipe. Frost on an exposed pipe, a bulge or a strange smell from a drain are other signs. Check other faucets in the house. If one pipe freezes, others may too.

How do I thaw a frozen pipe safely?

Keep the faucet open. As ice melts, running water helps melt the rest.
Apply gentle heat. Use a hair dryer, heating pad, space heater kept at a safe distance, or towels soaked in hot water.
Work from the faucet back toward the frozen section.
Keep going until full pressure returns.
Never use an open flame. Red Cross guidance, as reported by CBS News, warns against open-flame devices such as blowtorches, gas heaters and charcoal stoves.

If you cannot find or reach the frozen section, or it is inside a wall, call a plumber.

What if a pipe bursts?

Close the main shutoff valve right away. Turn off power to wet areas if you can do so safely from a dry spot. Open a faucet on the lowest level to drain the lines. Move belongings and take photos. Then call a plumber. Our guide on what to do when water comes through a ceiling covers the next steps.

Does insurance cover frozen pipes in Virginia?

This is general information, not insurance advice; every policy differs. Virginia's Bureau of Insurance consumer guide lists freezing of plumbing systems among the perils covered by some policy forms, and notes the HO-3 form excludes damage from freezing of an unoccupied building. Policies often expect you to keep heat on or shut off and drain the water. If you have damage, give your insurer immediate notice and protect the property from further harm.

How do I keep frozen pipes from happening again?

Insulate the pipes that froze, and the wall or crawl space around them.
Consider rerouting a pipe away from an exterior wall during a renovation.
Install frost-free hose bibs, which shut off water inside the warm wall.
Add a smart leak sensor near the water heater and main valve.
Replace a frozen pipe section with flexible PEX, which handles freezing better than rigid pipe.

Local note: Pipes on exterior walls are common in older homes in Falls Church and North Arlington. Pool houses and outbuildings in Great Falls need draining before winter. Garage water heaters and lines in Herndon townhomes are worth insulating.

Related reading: See water heater leaking: what to do, learn how to check for a leak with your water meter, and read about pinhole leaks in copper pipes.

When should you call a plumber?

Call when you cannot find or reach a frozen section, when the frozen pipe is inside a wall or ceiling, when you see a crack or bulge, or when a pipe has burst. Also call if water pressure does not return after thawing.

Frozen or burst pipe in McLean? Call (571) 760-4451 for a 24/7 emergency plumber from McLean Plumber Works.

Frequently asked questions

At what temperature do pipes freeze?

Water freezes at 32°F, but pipes inside a home usually freeze only after hours of much colder weather, especially when they run through unheated or poorly insulated spaces. Wind and how long the cold lasts matter as much as the low temperature.

Should I drip faucets every night in winter?

Not every night. Drip faucets fed by pipes on exterior walls or in cold spaces when a hard freeze is forecast. A slow trickle keeps water moving.

What temperature should I leave the heat on when I travel?

Keep the heat on while you are away. A common recommendation is no lower than 55°F, and higher if pipes run through cold spaces. Consider shutting off the main valve and draining lines for longer trips.

Is it safe to thaw a pipe with a hair dryer?

Yes, if the pipe is exposed and not leaking. Start near the faucet and work back. Never use a torch, open flame, charcoal stove or gas heater.

Does homeowners insurance cover frozen pipes?

Often, but conditions apply. Virginia's Bureau of Insurance guide notes some policies exclude freezing damage in an unoccupied building unless heat was kept on or the water was shut off and drained.