How to Winterize Your Home
(and Avoid a $5,000 Burst Pipe)
A burst pipe is the most expensive "small" failure in your house. A single frozen pipe that lets go can dump hundreds of gallons inside your walls and run $5,000–$15,000+ in water damage and repairs — and most of it is preventable with an afternoon of work and about $30 in materials. This guide walks the whole house, tells you what you can do yourself, what's worth paying for, and where the real risk hides.
We're not selling you anything. Most of this is free or nearly free.
Why This Matters More Than It Sounds
When water freezes it expands by about 9%. Inside a closed pipe, that expansion has nowhere to go, so pressure builds — not at the ice itself, but in the trapped water between the ice and a closed faucet. That's why a pipe usually bursts somewhere away from the actual frozen spot, and why simply "letting a faucet drip" works: it relieves the pressure that does the damage.
The pipes most at risk are the ones in unheated or poorly insulated spaces: exterior walls, attics, crawl spaces, garages, and along the cold north side of the house. If you only do one thing from this guide, protect those.
Start Here: The 15-Minute Freeze-Night Routine
When a hard freeze is in the forecast (roughly 20°F / −6°C or below, or a sharp drop after mild weather), do these the night before. They cost nothing.
- Open cabinet doors under sinks on exterior walls so household heat reaches the pipes. Kitchen and bathroom vanities are the usual culprits.
- Let a faucet drip — a slow, pencil-lead-thin trickle of cold water on the fixture farthest from where your water line enters the house. This keeps water moving and relieves pressure. The few cents of water is far cheaper than a burst pipe.
- Keep the thermostat steady, day and night — don't set it back at night during a freeze. Holding a constant temperature (at least 55°F / 13°C, even if you're away) keeps the inside of walls warmer.
- Open the garage's interior access and keep the garage door closed, especially if water lines or the water heater live out there.
These four moves prevent the large majority of freeze bursts. Everything below is about getting ahead of the problem before the cold even arrives.
The Outdoor Checklist — Do This First
Outdoor plumbing freezes first because it has the least protection. Tackle this early in the fall.
- Disconnect, drain, and store garden hoses. A hose left attached traps water against the spigot; when that freezes, it can crack the valve inside your wall where you won't see the leak until spring. One of the most common and most overlooked winter failures.
- Shut off and drain exterior faucets (hose bibs). If you have an interior shutoff for each outdoor spigot, close it, then open the outdoor faucet to drain the line and leave it open. If you have frost-free spigots, you still need to disconnect the hose for them to work as designed.
- Insulate exposed spigots with a $3–5 foam faucet cover from any hardware store.
- Blow out or drain irrigation and sprinkler systems. In freezing climates this is worth paying a pro for if you don't have an air compressor — a cracked underground irrigation line is an expensive, hard-to-find repair. It's cheap insurance.
- Drain and shut off any pool or outdoor water features per the manufacturer's instructions.
The Indoor Plumbing Checklist
- Insulate pipes in unheated spaces — crawl space, basement, attic, garage. Foam pipe sleeves cost about $1–3 per six feet and slide right on; this is genuinely easy DIY and one of the best dollar-for-dollar protections you can buy. Prioritize pipes on exterior walls and anything in a space that isn't heated.
- Seal air leaks near pipes. Cold air finding its way to a pipe through a gap around where it passes through a wall or floor is a common freeze cause. Caulk or use expanding foam around those penetrations.
- Know where your main water shutoff is — and that it works. If a pipe does burst, every minute counts. Find your main shutoff valve (often near where the line enters the house, in the basement, crawl space, or near the water heater), and make sure you can turn it. Tag it so anyone in the house can find it fast. This single piece of knowledge is the difference between a mop-up and a renovation.
- If you'll be away during winter, either keep the heat at 55°F minimum or fully winterize: shut off the main and drain the system. For long absences in cold climates, draining is the only fully safe option.
Your Heating System
- Replace the furnace filter. A clogged filter makes the system work harder, costs you in efficiency, and can cause the unit to overheat and shut down — exactly when you need it. A new filter is a few dollars and takes two minutes. Check it monthly through the season.
- Test your heat before you need it. Run the furnace for a cycle in early fall. If it's blowing cold, short-cycling, or making new noises, you want to find out in October when an HVAC tech is available — not during the first cold snap when everyone's furnace fails at once and you're paying emergency rates.
- Get a professional tune-up if it's been more than a year, especially for gas furnaces. A tech checks the heat exchanger for cracks (a carbon-monoxide safety issue), confirms safe combustion, and catches small problems before they strand you. This is one of the maintenance jobs genuinely worth paying for.
- Test every smoke and carbon-monoxide detector. Winter is peak CO season because of furnaces, space heaters, and sealed-up houses. Fresh batteries, working units — non-negotiable.
- Reverse your ceiling fans to clockwise on low; it pushes warm air that's collected at the ceiling back down, and it's free.
The Building Envelope
Where your heating dollars leak out — and where inexpensive fixes pay you back all winter.
- Seal drafts around doors and windows with weatherstripping and caulk. Cheap, DIY, and pays you back in lower heating bills immediately.
- Add door sweeps to exterior doors with a visible gap at the bottom.
- Check attic insulation. Heat rises and escapes through the attic first; if yours is thin or compressed, topping it up is one of the better long-term efficiency investments. Adequate attic insulation also keeps the roof deck cold, which helps prevent ice dams.
- Clean your gutters before the first freeze. Clogged gutters trap water that freezes, contribute to ice dams, and can force melt water under your shingles and into the house. We cover ice dams in detail — including the emergency steps if you already have one — in the ice dams guide.
- Trim branches that overhang the roof or hang near power lines — ice and snow load brings them down.
What's DIY vs. What's Worth a Pro
- Foam pipe sleeves on exposed pipes
- Foam faucet covers ($3–5 each)
- Disconnecting and storing garden hoses
- Swapping the furnace filter
- Weatherstripping and door sweeps
- The freeze-night routine
- Testing smoke and CO detectors
- Furnace tune-up (especially gas — the CO safety check matters)
- Sprinkler/irrigation blow-out if you don't own a compressor
- Insulation or air-sealing that means crawling an attic or crawl space
If you're getting quotes for a furnace tune-up, know the fair price range for your area before you call — and watch for the "free inspection" that magically discovers you need a whole new system.
The One Mistake That Floods Houses
Don't leave a garden hose connected over winter, and don't fully set back the thermostat during a hard freeze to save a few dollars. Those two small economies are behind a huge share of burst-pipe claims every year. The savings are pennies; the failure is five figures.
Quick Winterizing Checklist
Print this, screenshot it, or save it to your phone before the first cold snap.
- Disconnect, drain, and store all garden hoses
- Shut off and drain exterior faucets; cover spigots
- Blow out sprinkler / irrigation lines
- Insulate pipes in unheated spaces
- Seal air leaks around pipe penetrations
- Locate and test your main water shutoff
- Replace the furnace filter
- Test the furnace early in the season
- Schedule a furnace tune-up (if overdue)
- Test smoke and CO detectors
- Weatherstrip doors and windows
- Clean the gutters
- Set a freeze-night plan (drip faucets, open cabinets, steady heat)
Common Questions
What's the most important thing to do before a freeze?
Disconnect every garden hose from every outdoor spigot. A hose left attached traps water against the valve body inside your wall — when that freezes and cracks, the leak is hidden until spring. That one step prevents one of the most common and overlooked winter failures.
Why does dripping a faucet prevent frozen pipes?
When water freezes it expands about 9%, and in a closed pipe the expanding ice traps water between the ice and a closed faucet. That trapped water is where pressure builds — and where the pipe eventually bursts. Letting a faucet drip relieves that pressure. A pencil-lead-thin trickle is all you need.
What temperature should I keep my house if I'm away in winter?
At least 55°F (13°C). Below that, pipes in exterior walls and unheated spaces become vulnerable. For long absences in cold climates, fully winterizing — shutting off the main and draining the system — is the only fully safe option.
Do I need a pro to blow out my sprinkler system?
If you don't own a high-CFM air compressor, yes — it's worth the modest service fee. A cracked underground irrigation line is an expensive, hard-to-find repair. The blow-out is cheap insurance by comparison.
What's the first thing to do if a pipe bursts?
Turn off the main water shutoff immediately — before you assess damage, before you call a plumber. Know where it is before you need it. Tag it so anyone in the house can find it fast. That single piece of knowledge is the difference between a mop-up and a renovation.
This guide is general home-maintenance information, not a substitute for a professional inspection of your specific home. Climate, home age, and construction vary — when in doubt, especially on gas heating systems, have a licensed pro take a look.