How do I prevent frozen pipes, and what if one freezes?

Which pipes freeze first around here?

Water freezes when the pipe sits in air below freezing long enough. It doesn't take a record cold snap. A few nights in the teens with wind finding its way into a gap is enough.

In Philadelphia rowhomes, the front basement is the trouble spot. The water service comes in through the front wall, right under the sidewalk, and the meter and main shutoff sit there with it. That front wall is often uninsulated stone or block with a drafty basement window or an old coal chute beside it. In Fishtown, Kensington, and Port Richmond we thaw a lot of front-basement meters every winter.

In Lower Bucks, the risk moves to crawlspaces and slab homes. Levittown and Croydon split-levels and ranchers often have supply lines running through a vented crawlspace or along the slab edge, and kitchen sinks on an outside wall. Hose bibs without a frost-free valve freeze everywhere. Garages with a laundry hookup are another common one.

How do I keep pipes from freezing?

Most of this is simple and takes an afternoon in the fall. Do it before the first hard freeze, not after.

• Disconnect garden hoses and drain outdoor spigots. If you have an inside shutoff for the hose bib, close it and open the outdoor spigot to drain the line.
• Insulate exposed pipe in the basement, crawlspace, and garage with foam sleeves. Pay extra attention to the first few feet inside the front wall where the service enters.
• Seal the drafts. Foam or caulk around the service entry, basement windows, dryer vents, and any gap where you can feel cold air on the pipe.
• Keep the heat on, even when you're away. Set the thermostat no lower than the mid-50s and leave interior doors open so warm air reaches every room.
• Open cabinet doors under sinks on exterior walls during cold snaps.
• Let a thin stream of cold water run from the faucet farthest from the meter on the coldest nights. Moving water is much harder to freeze.
• Close crawlspace vents for the winter and check that the crawlspace door seals.

How do I know a pipe has frozen?

The first sign is usually a faucet that won't run, or only trickles, while others in the house work fine. Sometimes there's frost on the outside of the pipe or a section that's bulging. If you turn on the tap and hear nothing at all, and it's been below freezing overnight, assume a freeze until you prove otherwise.

Trace the line back from the dead faucet toward the meter. Feel for the coldest section of pipe. That's where the ice is. In a rowhome it's usually within a few feet of the front wall. In a Bucks County crawlspace, it's near a vent or the point where the pipe runs closest to the outside.

One more sign that matters: water is running from a faucet you didn't open, or you hear water inside a wall. That means the pipe has already split and the ice plug has started to let go. Go straight to the main shutoff.

How do I thaw a frozen pipe safely?

Do these steps in order. The order is what keeps a frozen pipe from becoming a wet basement.

• Find and close the main water shutoff first. If the pipe cracked while frozen, the crack won't leak until the ice melts. With the main closed, you control what happens next.
• Open the faucet the frozen line feeds, both hot and cold. This gives the melting water and any steam a place to go and relieves pressure on the pipe.
• Warm the pipe slowly, starting at the faucet end and working back toward the frozen section. Use a hair dryer, a heating pad wrapped around the pipe, warm towels, or a space heater set a safe distance away. Keep the heat moving; don't park it on one spot.
• Keep going until full flow returns at the faucet. Then check the whole run for drips, bulges, or wet spots before you reopen the main.
• Never use a propane torch, an open flame, or a heat gun on high. Open flame can ignite framing and insulation, and rapid heating can crack the pipe.

What if the pipe has already burst?

Close the main shutoff, then open faucets to drain the lines. If water reached anything electrical, stay away from that area and cut power at the panel if you can do it safely. Move what you can out of the water and start toweling up.

Then call us. Burst pipe repair is a plumbing repair job we handle every winter: cutting out the split section, replacing it, checking the rest of the run for stress, and getting the house back on water. We look for why it froze in the first place, whether that's a drafty service entry, an uninsulated crawlspace run, or a supply line routed where it should never have been. If the water service itself froze and split under the front walk, our underground crews handle that work, with permits pulled through Philadelphia L&I or your township.

We offer 24-hour emergency service. Request service or call, and we'll walk you through what to shut off while we're on the way.