What do you do before a hard freeze?
Updated August 2026
When a hard freeze is on the way, disconnect and drain the garden hoses, shut off and drain the exterior faucets and irrigation, open the cabinet doors under sinks on outside walls, and let one faucet drip overnight. Find your main water shutoff before you need it. A pipe that bursts can push hundreds of gallons an hour into the house, while pipe insulation that prevents it costs just $1 to $3 a foot. Unprotected pipes start freezing once it drops near 20°F.
| Task | Interval | Effort |
|---|---|---|
| Disconnect, drain, and store garden hoses | Before the freeze | 10 min · DIY |
| Shut off and drain outdoor faucets and irrigation | Before the freeze | 20 min · DIY |
| Open cabinet doors under exterior-wall sinks | Before the freeze | 2 min · DIY |
| Set one or two faucets to a pencil-thin drip | Overnight | 2 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Hold the thermostat at 65°F day and night | During the freeze | Set once |
| Locate and test the main water shutoff | Before you need it | 5 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Insulate exposed pipes in attics, garages, crawl spaces | Yearly | $1–3 per foot |
| Add insulated covers to exterior spigots | Yearly | $2–10 each |
What neglect costs
A single pipe that splits behind drywall can release hundreds of gallons an hour, and freeze losses rank among the costliest home-insurance claims, commonly $5,000 to $15,000 in water and mold remediation once floors, cabinets, and drywall are soaked. A vacant house whose heat failed can lose every level at once. The prevention, an hour of hose-and-faucet work plus a few dollars of foam, is trivial next to the bill. If you will be away for the cold stretch, the winterizing checklist covers draining the system down.
Leave these to a pro
Most freeze prep is DIY, but a plumber earns two calls: blowing out an in-ground sprinkler system in fall (roughly $75–150) so buried lines do not crack, and adding frost-proof sill cocks or heat cable to any pipe that has frozen before ($150–400 installed). If a pipe does freeze, a pro can thaw it safely before it splits, and if you cannot find the shutoff or a line has already burst, that is a same-day emergency call, often $150–350 just to get someone out.
This whole checklist ships as reminders in OnOtto: every task above, on the right schedule for your home, snooze-proof.
Load this checklist as remindersFrequently asked questions
At what temperature do pipes actually freeze?
Unprotected pipes in unheated spaces start to freeze when the air around them drops to about 20°F, though wind and poor insulation can push the risk higher. Pipes in exterior walls, attics, garages, and crawl spaces go first because they are coldest. A hard freeze warning, several hours below 20°F, is your cue to run the full list. In a mild climate where homes are not built for cold, damage happens at higher temperatures because pipes were never insulated in the first place.
Should I really leave a faucet dripping all night?
Yes, during a hard freeze. A pencil-thin trickle keeps water moving so it cannot freeze solid, and it relieves the pressure that actually bursts a pipe, the ice pushing against a closed faucet, not the ice itself. Drip the faucet farthest from where the line enters the house, and pick one on an exterior wall. The wasted water costs pennies against a five-figure flood, and running both hot and cold protects both supply lines.
What do I do if a pipe already froze?
Shut off the main water immediately so that when the pipe thaws it does not flood, then open the affected faucet so melting water and steam have somewhere to go. Warm the frozen section gently with a hair dryer, a space heater, or towels soaked in hot water, working from the faucet back toward the cold spot. Never use an open flame or a torch. If you cannot reach the pipe or it has already split, leave the main off and call a plumber.
Do I still need to drip faucets with PEX pipe?
PEX tolerates freezing far better than copper because it can expand, so it bursts less often, but it is not freeze-proof. The fittings and any copper stubs at fixtures can still fail, and repeated freeze cycles fatigue the material. In a hard freeze, keep dripping a faucet and keep exposed PEX insulated; the plastic buys you margin, not immunity. Treat it like any other pipe when the temperature falls near 20°F.