Colorado is hard on pipes because it swings. A 70-degree afternoon can turn into a single-digit night, and the pipe that was fine all week freezes in a few hours. Most frozen pipes we see were preventable with a few minutes of prep.
What temperature do pipes freeze?
Water freezes at 32°F, but pipes inside a heated house usually aren't in danger until it's a lot colder outside. A common rule of thumb is that trouble starts around 20°F and below, and sooner for pipes in exterior walls, crawl spaces, garages, and anywhere a draft blows across them. Wind matters too: it doesn't make a pipe colder than the air, but it pushes cold air into every gap around the house.
Will it get that cold where you live? Check tonight's forecast for your city →
Before the first hard freeze
- Disconnect every garden hose. A frost-free faucet can't drain with a hose attached. How to winterize outdoor faucets →
- Blow out the sprinkler system and protect the backflow preventer. Sprinkler blowouts →
- Shut off and drain older, non-frost-free outdoor faucets from the inside valve, and leave the outside spigot open for the winter.
- Insulate exposed pipes in crawl spaces, unheated garages, and basements with a cold corner. Foam sleeves are cheap. For a line that keeps freezing, self-regulating heat cable installed to the manufacturer's instructions can help.
- Seal drafts near pipes: gaps around the rim joist, crawl-space vents, dryer vents, and where lines pass through exterior walls.
- Find your main water shutoff and make sure it turns. How to find it →
When a cold snap is coming
- Keep the thermostat at 55°F or higher, day and night. A big nighttime setback is when exterior-wall pipes freeze.
- Open the cabinet doors under kitchen and bathroom sinks on exterior walls so room heat can reach the pipes.
- Let those faucets drip slightly, hot and cold. Moving water is much harder to freeze, and a drip relieves pressure if ice does form.
- Keep the garage door closed if there are water lines in the garage or the wall next to it.
- If a room has had a frozen pipe before, give that room extra heat.
If you're traveling
Leave the heat at 55°F or higher, and ask someone to check the house during cold weather. For a longer trip, shut off the main water valve and open a faucet on the lowest floor to drain the pressure. Then, if a pipe does freeze, very little water can escape. Set the water heater to vacation or pilot while you're gone.
Vacant houses and rentals
An empty house is where a frozen pipe does the most damage, because it can run for days before anyone notices. If a property will sit empty over the winter, either keep the heat on and the water off, or have it fully winterized. Our guide covers both: How to winterize a vacant house in Colorado.
Signs a pipe is frozen
- A faucet gives a trickle or nothing on a very cold morning while others work
- Frost on an exposed pipe, or a section that's bulging
- A toilet that won't refill
If it's frozen but not leaking, open the faucet and warm the pipe gently: what to do with a frozen pipe. If it has already split and water is running, shut off the main and call (720) 818-5569. Frozen and burst pipe repair →