How to Thaw Frozen Pipes Safely

On a cold Colorado morning, you turn on the kitchen faucet and get a trickle, or nothing at all. That usually means ice is blocking a supply line somewhere between the main and the faucet. The good news: if you act carefully, you can often thaw it before it bursts. The bad news: a frozen pipe may already have a split that won't leak until the ice melts. Here's how to handle both.

Signs your pipes are frozen

• Little or no water from a faucet during very cold weather
• Frost on the outside of an exposed pipe
• A toilet that doesn't refill after flushing
• Strange smells from drains, because blocked lines can't vent properly
• A bulge or crack in a visible pipe

If only one faucet is affected, the frozen section is usually on the line feeding that fixture, often where it runs through an exterior wall, a crawl space or a garage. If the whole house has no water, the ice may be near where the main line enters.

Before you start: check for a burst

Look along any exposed pipe for cracks, bulges or wet spots. If you see a split, don't thaw it yet. Shut off the main water valve first. Our guide on how to shut off the water to your house shows where to find it. Thawing a split pipe without shutting off the water will turn a frozen pipe into a flood.

How to thaw a frozen pipe, step by step

• Open the faucet. Turn on both hot and cold at the fixture the pipe feeds. This relieves pressure and lets water escape as the ice melts.
• Find the frozen section. Start at the faucet and work backward along the pipe. Look for frost or a section that feels much colder.
• Apply gentle heat. Use a hair dryer, an electric heating pad wrapped around the pipe, or towels soaked in hot water. Start closest to the faucet and work toward the ice, so melting water has somewhere to go.
• Warm the space. Open cabinet doors under sinks and set a space heater nearby, following the manufacturer's safety instructions and keeping it away from anything that can burn.
• Keep heating until full pressure returns. A trickle means some ice is still in the line.
• Check every other faucet. If one pipe froze, others in similar spots may have too.
• Watch for leaks. Once water flows, check along the pipe, under the sink and on the ceiling below for drips.

What never to do

• Never use a propane torch, open flame or charcoal stove to thaw pipes. The Red Cross warns this is a serious fire hazard.
• Never leave a space heater unattended or near curtains, bedding or paper.
• Never pour boiling water directly on PVC or PEX pipe.
• Never use electrical devices while standing in water.
• Never try to thaw a pipe you can't reach by cutting into a wall yourself if you aren't sure what's behind it.

Thawing pipes in walls, crawl spaces and garages

Inside a wall. Turn up the heat and point a space heater or infrared lamp at the wall, keeping a safe distance. If that doesn't work within a reasonable time, call a plumber. Opening the wall may be needed.

In a crawl space. Make sure it's safe to enter, then use a hair dryer or heating pad on the pipe. Block drafts from vents during the cold snap.

In a garage. Close the garage door, warm the space with a safe heater and apply gentle heat to the pipe.

Outdoor spigots. A spigot that froze with a hose attached may have split the pipe inside the wall. When it thaws, check the basement or the wall behind it for water.

What if the pipe burst?

If you see water spraying, dripping from a ceiling or pooling on a floor:

• Shut off the main water valve right away.
• Turn off power to the wet area if you can do so without standing in water.
• Open a faucet on the lowest floor to drain the line.
• Take photos of the damage before cleanup starts.
• Call a plumber to repair the pipe, and a water damage company to remove the water and dry the structure.

Water from a burst pipe can soak into walls, insulation and subfloor quickly. The faster it's extracted and dried, the less material needs to be replaced. In Englewood and the south Denver metro, our team handles burst pipe water damage 24/7.

Will insurance cover it?

The Colorado Division of Insurance says burst pipes and the water damage they cause are generally covered by homeowners and renters policies. Policies may exclude damage if you didn't take reasonable steps to keep a vacant home heated. Our water damage insurance claim guide explains what to document.

How to keep pipes from freezing next time

Denver Water also recommends knowing where your main shutoff is before winter starts.

When to call a pro

Call a plumber if you can't find the frozen section, the pipe is inside a wall or ceiling, or it doesn't thaw after a reasonable effort. Call a water damage restoration company if water got into walls, ceilings, floors or a finished basement. Hidden moisture is how a one-day plumbing problem becomes a mold problem.