How to Prevent Frozen Pipes in Your Denver Home (And What to Do If One Freezes)

Denver winters swing fast. A sunny 50-degree afternoon can turn into a single-digit night, and that sudden drop is exactly when pipes in exterior walls, crawl spaces, garages and unheated basements freeze. A frozen pipe is more than an inconvenience: water expands as it freezes, pressure builds behind the ice, and the pipe can split. When it thaws, that split can release water into walls, ceilings and floors.

The good news is that most frozen pipes are preventable with a few inexpensive habits. This guide covers how to protect your plumbing before a cold snap, what to do during one, how to safely thaw a frozen pipe, and when it is time to call a plumber.

Quick Answer: How Do You Keep Pipes From Freezing?

Keep warm air around your pipes and keep water moving. Insulate exposed pipes, open cabinet doors under sinks on exterior walls, keep the garage door closed, disconnect garden hoses, let the faucet farthest from where water enters your home drip slowly during a deep freeze, and keep your thermostat at 65°F or higher, even when you are away. Know where your main water shut-off valve is before you need it.

Why Pipes Freeze in Denver Homes

Pipes freeze when the water inside them is exposed to sustained below-freezing air. In Front Range homes, the usual trouble spots are:

• Pipes on exterior walls, especially under kitchen and bathroom sinks.
• Unheated or partially finished basements and crawl spaces.
• Attached garages, where supply lines often run to laundry rooms or upstairs bathrooms.
• Outdoor spigots (hose bibs) and sprinkler lines that were not drained in the fall.
• Attics and soffits in older homes and some additions.

Wind and air leaks matter as much as temperature. A small gap around a dryer vent or a rim joist can direct freezing air straight onto a water line.

Before Winter: 7 Ways to Protect Your Pipes

1. Find and test your main shut-off valve. In most single-family homes it is in the basement or crawl space, on the wall facing the street. Make sure it turns and that everyone in the house knows where it is.
2. Disconnect and drain garden hoses. A hose left attached traps water in the spigot. If you have a non-frost-free hose bib, shut off its interior valve and open the outside tap to drain it.
3. Blow out irrigation lines before the first hard freeze.
4. Insulate exposed pipes in basements, crawl spaces and garages with foam pipe sleeves. For problem spots, a UL-listed heat cable installed to the manufacturer’s instructions adds protection.
5. Seal air leaks near pipes: rim joists, sill plates, and penetrations where lines enter the house.
6. Service your furnace so heat does not fail on the coldest night of the year.
7. Consider a smart leak detector or water-flow sensor near the water heater, washer and under sinks for early warning.

During a Cold Snap: What to Do

• Open cabinet doors under sinks on exterior walls so warm room air can reach the pipes.
• Let a faucet drip. Choose the faucet farthest from where water enters your home and let it drip slowly. Place a bucket underneath to save the water for plants or cleaning.
• Keep the garage door closed if plumbing runs through the garage.
• Keep the thermostat steady, day and night. Saving a few degrees overnight is not worth a burst pipe.
• Traveling? Keep the heat at 65°F or higher, ask someone to check the house, and consider shutting off the main water valve while you are gone.

Signs a Pipe Is Frozen

The most common sign is simple: you turn on a faucet and only a trickle comes out, or nothing at all. Other clues include frost on an exposed pipe, a bulge in the line, an unusual odor from a drain, or one fixture working while another in the same area does not.

How to Safely Thaw a Frozen Pipe

1. Shut off the water at the main valve, or at least confirm it works, so you can stop a sudden gush if the pipe has split.
2. Open the faucet the pipe feeds so melting water and steam have somewhere to go.
3. Warm the pipe slowly, starting near the faucet and working back toward the frozen section. A hair dryer, a space heater kept at a safe distance, or warm towels work well.
4. Never use an open flame such as a propane or blow torch. It is a fire hazard and can damage the pipe.
5. Check for leaks once water is flowing again, including inside nearby walls and ceilings.

If you cannot reach the frozen section, cannot find it, or the pipe is inside a finished wall, stop and call a licensed plumber. Denver Water also publishes practical tips for preventing and thawing frozen pipes.

What to Do If a Pipe Bursts

1. Turn off the main water valve immediately.
2. Turn off electricity to any area where water is near outlets, fixtures or appliances, if you can do so safely.
3. Move belongings out of the way and start removing standing water.
4. Take photos for your insurance company.
5. Call a plumber to repair the line, then have hidden moisture checked. Lingering water can lead to mold and rot; our guide to the early warning signs of a water leak explains what to watch for afterward.

Long-Term Fixes That Prevent Repeat Freezes

If the same pipe freezes every winter, the real fix is usually structural rather than a habit. Options include rerouting a supply line away from an exterior wall, adding insulation and air sealing in a rim joist or crawl space, replacing an old hose bib with a frost-free model, or finishing a cold basement area so it stays heated.

BlueJay’s Denver plumbing services cover leak repair, fixture replacement and repiping problem lines, and our basement finishing team can insulate and enclose cold spaces as part of a larger project.

Frequently Asked Questions

Need help? If a pipe keeps freezing or you need a leak repaired before winter gets worse, Call BlueJay at 720-231-8779 or request a free estimate. We serve homeowners across Denver, Boulder and the surrounding metro area.