How to Winterize Your Home’s Plumbing

Winterizing means emptying water out of a home’s plumbing so nothing is left inside the pipes, fixtures, and tanks to freeze, expand, and crack the system while the building sits cold. It is a specific job for a specific situation: a house that will lose its heat for the winter. A second home, a property between tenants, a cabin you close up in October, or any structure where the furnace will be off and the indoor temperature can drop below freezing. The goal is simple to state and easy to get wrong in the details. Get the water out of every spot that holds it, and protect the few spots that will not fully drain.

This guide walks the drain-down in the order that actually works, because order is what most “winterize your plumbing” lists leave out. They give you a pile of tips. What you need is a sequence. Below is one ordered procedure, plus the spots that quietly hold water and crack anyway even after you think the system is empty.

A quick boundary before you start. Winterizing is not the same as keeping a heated, occupied home from freezing during a cold snap. If your house stays warm and lived in, you do not drain anything. For that situation, see our guide on how to prevent pipes from freezing (125), and for the question of running a trickle overnight, see our guide on whether to leave faucets dripping in a freeze (130).

When Full Winterizing Is Necessary vs. Just Leaving the Heat On

Full winterizing is necessary only when the home will be unheated and unmonitored through freezing weather. If you can keep the heat on at a minimum setting and someone checks the house, draining the whole system is usually overkill. If the heat will be off, draining is the safer choice, because a burst pipe in an empty home runs unnoticed and floods for days.

Use this decision in plain terms. Heat staying on, even at a low thermostat setting, plus someone looking in or a freeze alarm watching the temperature: you can leave the system charged and skip the full drain. Heat going off completely, or a long unmonitored stretch where a power outage could kill the furnace: drain the system. The risk is not just the cracked pipe. It is the water that keeps flowing through that crack while no one is home to shut the main.

The deeper a home gets into the “off and empty for months” category, the more draining wins. A weekend away with the heat set to 55 degrees is not a winterizing job. A lake house closed until April is. For the full decision framework on vacancy length and monitoring, see our guide on how to protect plumbing in a vacant or vacation home (129).

The U.S. Department of Energy is blunt about the stakes of getting this wrong: if the water in your pipes starts freezing, you run the risk of that pipe exploding. Pipes in colder parts of a house, like crawl spaces and attics, are the most exposed. Once you decide to drain, do it completely. A half-drained system can be worse than a full one, because the water left behind sits in low spots with nowhere to expand.

Shutting Off the Main and Draining the System From the Lowest Point Up

Start by closing the main water shutoff, then drain the supply lines from the top of the house down so gravity pulls the water out through the lowest open faucet. This is the backbone of the whole job. Everything else protects the spots this step cannot reach.

Here is the safe DIY sequence for the supply side:

1. Close the main water shutoff valve, usually located where the water line enters the home, often near the meter, in a basement, or in a utility area.
2. If your water heater has its own shutoff, and before you do anything to the heater itself, cut power or gas to it. More on that below, and it is not a step to improvise.
3. Open the highest faucets in the house first, both hot and cold handles, so air can enter the lines.
4. Work downward floor by floor, opening every faucet, tub, and shower.
5. Open the lowest faucet or drain valve last so the water in the supply pipes runs out the bottom of the system.
6. Outside, close the inside valve that feeds each hose bib, then open the outdoor spigot to let it drain.

The point of going lowest-faucet-last is that water runs downhill. Opening a low drain while high faucets stay shut just traps a vacuum. Opening the high ones first lets air push the column of water down and out. If your home has a dedicated low-point drain valve on the supply line, that is your final exit.

The Red Cross gives the standard outdoor step for this season: remove, drain, and store hoses used outdoors, close the inside valves supplying outdoor hose bibs, and open the outside hose bibs to allow water to drain. The same logic applies to in-ground sprinklers, which hold water in buried lines that gravity alone will not clear. For the outdoor faucet and hose bib procedure in detail, see our guide on how to winterize outdoor faucets and hose bibs (160), and for irrigation lines, see our guide on how to winterize a sprinkler or irrigation system (163).

Clearing Faucets, Toilets, and Traps of Standing Water

After the supply lines drain, water still sits in three places that gravity does not empty: toilet tanks and bowls, fixture traps, and the curved low spots under sinks and tubs. These are the spots that crack after homeowners think the system is dry. Clear them deliberately.

For toilets, the fixture holds water in two separate places. Drain both:

1. Shut the supply stop behind the toilet if it has one, or rely on the main already being closed.
2. Flush and hold the handle to push most of the tank water out.
3. Sponge or bail the remaining water out of the tank.
4. Plunge or bail the bowl down so the standing water in the bowl trap is mostly gone.

For sink, tub, and shower traps, you cannot drain them by gravity. A P-trap is built to hold water on purpose, which is exactly why it freezes. To learn what that curved section is and why it stays full, see our guide on what a P-trap is and the job it does (004). You will not get a trap dry by opening the faucet above it. The water sitting in the bend stays put. That trapped water is handled in the antifreeze step below, not by draining.

Do not skip the floor drains, the washing machine connections, and any rarely used fixture like a basement utility sink. Each one has a trap holding water. A bathroom you forget on the second floor is a cracked trap in February.

Draining the Water Heater for the Season

Draining a water heater for winter means cutting its power or gas first, then emptying the tank, and this is the point where the job stops being a simple drain-down. Get the power-off step wrong and you can destroy the heater or create a real hazard. If you are not fully comfortable with gas appliances or electrical panels, this is a licensed plumber’s job.

Why the order matters so much. On an electric water heater, the heating elements must stay submerged. If power reaches an element while the tank is empty, the element can dry-fire and burn out in well under a minute. On a gas water heater, the burner and pilot must be shut down before you drain, and relighting later involves gas. The general safe practice, confirmed across manufacturer guidance, is to cut the energy source first, let the tank cool, close the cold water supply to the heater, then drain. Refilling completely before any power or gas goes back on is just as critical, because energizing a partly empty tank is what damages it.

That is the concept. The exact steps vary by model, and the gas relight and any work on gas connections are not DIY territory here. For anything involving the gas valve, the pilot, or the burner, follow the manufacturer’s instructions to the letter or call a licensed plumber. We do not give a gas relight procedure in this guide. If you smell gas at any point, leave the building and call your gas utility from outside. For shutting off gas to the appliance safely, see our guide on how to safely shut off gas to a plumbing appliance (136).

If draining the heater feels like more than you want to take on, you have a reasonable middle option for a short closure: leave the tank full and the energy off, and accept that a full tank in a hard freeze can still be at risk. For a long, deeply cold closure, the tank should come empty. When in doubt, hand the water heater step to a professional.

Where to Add Non-Toxic Plumbing Antifreeze (Traps and Bowls)

Pour non-toxic, plumbing-rated antifreeze into every spot that will not drain: each sink, tub, shower, and floor-drain trap, plus the toilet tanks and bowls after you have emptied what you can. This is the step that protects the water you physically cannot remove. Use the right product, and only the right product.

Use propylene glycol antifreeze, the kind sold for RV and marine plumbing systems, and never automotive antifreeze. This is not a preference, it is a safety line. The CDC’s toxicology agency states the difference plainly: ethylene glycol, the base of most automotive antifreeze, is a potent cause of acute toxicity in humans, while propylene glycol is a “generally recognized as safe” additive for foods and medications by the FDA. Automotive antifreeze poured into a home plumbing system poisons a line that may carry drinking water again in spring. Plumbing antifreeze is made to sit in that system safely.

Where to put it, once supply lines are drained and traps are emptied of what gravity will give you:

1. Pour enough into each fixture trap to fill the bend and create a freeze-proof barrier in the curve.
2. Add a small amount to each toilet tank.
3. Pour some directly into each toilet bowl so it mixes with the small amount of water left in the bowl trap.
4. Do not forget floor drains, the washing machine standpipe, and any seldom-used trap.

A note on the water heater and antifreeze: do not pour antifreeze into a drained water heater tank or the supply lines feeding it as a shortcut. Antifreeze belongs in traps and bowls, the spots that cannot drain. Supply lines should be emptied, not filled with antifreeze, unless you are following a specific blow-out and antifreeze procedure for a system that cannot be fully drained.

This is general information for winterizing a home plumbing system and is not professional advice. Conditions vary by home, and gas and water-heater work in particular can be hazardous.

The Walk-Through Before You Lock Up

Before you leave, walk the house once with a checklist in hand and confirm every water-holding spot is either drained or protected with antifreeze. The walk-through catches the one fixture you forgot, and one forgotten fixture is the whole point of failure.

Go room by room and confirm:

• Main shutoff closed, and the lowest drain point opened and then left as your system requires.
• Every faucet opened and run dry, hot and cold, on every floor.
• Both toilet tanks and bowls emptied, then dosed with antifreeze.
• Every trap protected with antifreeze, including floor drains, the laundry standpipe, and any basement or guest fixture.
• Water heater off at the power or gas source, and drained or intentionally left full per your plan.
• Outdoor hose bibs drained, inside feed valves closed, hoses removed and stored.
• Sprinkler and irrigation lines cleared, or scheduled to be.

Leave a written note for yourself or the next person about which valves are closed and which appliances are off. Come spring, you do not want to guess whether the water heater was drained or just powered down. When you return, refill and re-pressurize slowly, open faucets to bleed air, and confirm the water heater tank is completely full before restoring its power or gas.

If you find a pipe has frozen or burst while the home was closed, do not improvise repairs under pressure. For what to do at that moment, see our guide on what to do if a frozen pipe bursts (127) and our guide on how to thaw frozen pipes safely (126). And if you are weighing all this against simply keeping the home warm instead, our guide on why pipes freeze and which ones are most at risk (124) explains which parts of the house drive the decision.

Frequently Asked Questions

Do I really need to drain the pipes, or can I just turn the heat down?
It depends on how cold the home will get and whether anyone is watching it. If the heat stays on at a low setting and someone checks in or a freeze alarm is in place, you can usually leave the system charged. If the heat goes off completely or the home sits unmonitored for a long stretch, drain the system, because an undetected burst in an empty house floods for days.

What antifreeze do I use for home plumbing?
Use propylene glycol antifreeze sold for RV and marine plumbing, which is labeled non-toxic. Never use automotive antifreeze, which is usually ethylene glycol and is acutely toxic to people and pets. The plumbing-rated product is made to sit safely in a system that may carry drinking water again later.

Why do traps and toilet bowls crack even after I drain the pipes?
Because draining the supply lines does not empty them. A P-trap is designed to hold water in its curve, and a toilet bowl always keeps water in its built-in trap. That standing water freezes and expands. The fix is to pour plumbing antifreeze into every trap and bowl after the rest of the system is drained.

Should I drain the water heater myself?
Only if you are comfortable cutting its power or gas first and refilling it completely before restoring energy. An electric element can burn out fast if the tank is empty when powered, and gas work carries its own hazards. If any of that feels uncertain, leave the water heater to a licensed plumber.

How do I bring the system back in spring?
Close the low drain points, then slowly reopen the main shutoff to refill and re-pressurize the lines. Open faucets to let trapped air escape, flush the antifreeze out of traps and bowls, and confirm the water heater tank is completely full before turning its power or gas back on.

Sources

U.S. Department of Energy, Turn Down the Temperature, but Don’t Let Your Pipes Freeze!: https://www.energy.gov/energysaver/articles/turn-down-temperature-dont-let-your-pipes-freeze
American Red Cross, Preventing and Thawing Frozen Pipes: https://www.redcross.org/get-help/how-to-prepare-for-emergencies/types-of-emergencies/winter-storm/frozen-pipes.html
Agency for Toxic Substances and Disease Registry (CDC), Ethylene Glycol and Propylene Glycol Toxicity, What Is Propylene Glycol?: https://archive.cdc.gov/wwwatsdrcdcgov/csem/ethylene-propylene-glycol/propyleneglycol.html
U.S. EPA WaterSense, Sprinkler Spruce-Up: https://www.epa.gov/watersense/sprinkler-spruce-up