How to winterize home plumbing depends on one question: will the house stay heated and lived in, or sit empty? An occupied home needs insulation, steady heat, and closed-off outdoor lines. A vacant or seasonal home needs a full drain-down, so no water is left in the pipes to freeze and split them.

Both jobs matter here. Much of the housing in Danbury, Bethel, Newtown, Ridgefield, and New Milford is older, with pipes running through crawl spaces, garages, and outside walls. Many homes across Fairfield County and Westchester also run on private wells, which adds a pump and pressure tank.

Plan to finish this in fall, while a mild day still makes the work easy. All State Plumbing Pros handles winterization as part of our residential plumbing service. This guide walks through what we check, so you can do the basics yourself or know what to ask for.

Which pipes need to be winterized?

Any pipe that runs through an unheated space or sits near cold outside air needs winterizing. That covers pipes located in crawl spaces, attics, unheated basements, and garages, plus water lines inside exterior walls and under a kitchen sink or vanity on an outside wall. Outdoor faucets, sprinkler systems, and pool supply lines are on the list too. In our experience, the trouble spots in older homes are the ones nobody looks at, like a supply line along a cold rim joist or a bathroom built over an uninsulated crawl space. Walk the basement with a flashlight and note every exposed pipe first.

At what temperature do plumbing pipes freeze?

Water freezes at 32°F, but there’s no single outdoor temperature at which every pipe freezes. The risk climbs as temperatures drop and cold spells drag on, especially in unheated spaces. The American Red Cross notes that frozen pipes often turn up against exterior walls or where the water service enters through the foundation. The main line is buried below the frost line, so the weak spot is usually where it comes up into the house.

Freezing does damage because ice takes up more room than liquid water. The USGS notes that ice is about 9 percent less dense than water. As ice forms, it pushes outward and builds pressure in the water trapped ahead of it, and that pressure can split copper and crack fittings.

Occupied home or vacant home: which winterization do you need?

If the house stays lived in with the heat on, you need prevention, not a drain-down. If the house will sit empty for weeks or months, drain the plumbing completely. Homeowners often ask us whether leaving the heat on is enough for a vacant house. The Red Cross advises leaving the heat at no lower than 55°F when you’re away, and that’s the baseline. A furnace can still fail or lose power while nobody is there, so for a long absence, many owners also shut off the main water valve and drain the lines.

How to winterize an occupied home

For a home that stays heated, the goal is to keep warmer air around the pipes and cold air away from them. Our frozen pipe prevention guide, linked below, covers each step in detail. The short version:

• Add pipe insulation to exposed hot and cold water pipes in garages, basements, and under-sink cabinets.
• Add insulation to attics, basements, and crawl spaces.
• Seal drafts around foundation vents and where pipes pass through outside walls.
• If water lines pass through the garage, keep its door shut on cold days.
• Open kitchen and bathroom cabinet doors on very cold nights, with cleaners moved out of children’s reach.
• Keep the thermostat at the same setting day and night.
• In extreme temperatures, let cold water drip from faucets served by exposed pipes. Even a trickle of running water helps.

For outdoor faucets, disconnect, drain, and store garden hoses, then close the indoor shutoff valve that feeds each hose bib. Open the outside faucet and leave it open, so any water left in the pipe can drain and has room to expand. A hose left attached traps water in the faucet, which is how a lot of hose bibs split.

How to drain water pipes to keep from freezing in a home

To drain a home’s plumbing, shut off the main water valve, open every faucet from the top floor down, and drain the system at its lowest point. Then empty the toilets and water heater. A pipe that’s completely dry has nothing to freeze. This is the order we follow for a vacant or seasonal house:

1. Shut off the water at the main valve, usually in the basement near the water meter. Turn it slowly and don’t force it.
2. On a private well, turn off power to the well pump at the breaker.
3. Open all hot and cold faucets, starting on the top floor and working down. Open each shower valve too.
4. Drain at the lowest point, usually a basement faucet or a drain valve on the main line. A garden hose can carry the water to a floor drain, sump pit, or outside.
5. Flush all toilets to empty the tanks and bowls, and sponge out what’s left.
6. Turn off and drain the water heater (see below).
7. Run the dishwasher and washing machine briefly to clear their lines.
8. Pour non-toxic RV antifreeze into every sink, tub, and shower trap and into each toilet bowl.
9. Leave the faucets open and tag the main valve so no one turns the water back on early.

Use only RV or plumbing antifreeze, the non-toxic propylene glycol type, and never pour antifreeze into the water supply lines. It goes in the traps, which hold water by design, and in the toilets. On town water, the curb stop valve near the street can isolate the service line, but many utilities want to operate it themselves, so call your water department first. The last step is blowing out the lines with compressed air. An air compressor pushes residual water out of low spots that gravity can’t empty, but too much pressure can damage older fittings, so we treat it as a professional step.

Draining the water heater

Shut off the power to an electric water heater, or set a gas unit to off or vacation mode, before you drain it. Close the cold supply valve, hook a hose to the drain valve at the bottom, and open a hot tap upstairs so air can enter as the hot water tank empties. Follow the manufacturer’s instructions for your model. In our experience, the hot water heater is the step people skip most often. When you reopen the house, refill the water heater tank completely before turning the power or gas back on. Our water heater repair and installation team can handle both.

Winterizing a private well system

On a private well, winterizing also means protecting the pump, the pressure tank, and any piping in a well house or unheated space. If the house stays heated, insulate exposed well piping and keep the pressure tank in a space that stays above freezing. For a vacant home, turn off power to the pump, drain the pressure tank, and drain the house lines as described above. We see a lot of private wells in northern Fairfield County, and the tank and pressure switch are easy to overlook. Our well pump service team can walk you through how your setup drains.

Sprinkler systems and pool supply lines

Sprinkler systems and swimming pool supply lines should be drained exactly as their manufacturer or installer directs, with no antifreeze added unless they tell you to. That guidance comes from the American Red Cross frozen pipe guide. Irrigation lines run shallow, so they feel cold temperatures well before your main water supply does. Plan to have them cleared before the ground freezes.

How much does a plumber charge to winterize a house?

The cost depends on the size of the house, the number of fixtures, whether there’s a well or a sprinkler system, and travel time. Angi’s national cost guide is a useful starting point, though its figures cover whole-house winterizing and not plumbing alone.

Source: Angi’s guide to the cost to winterize a house (2025 data). Local prices vary, and All State gives a free estimate with upfront pricing before any work starts.

What a professional winterization includes

A professional winterization covers the full drain-down plus the steps that are hard to do well on your own. A plumber locates and tests the shutoff valves, drains the plumbing pipes and water heater, blows out the lines with an air compressor, adds antifreeze to the traps and toilets, and flags exposed pipes that need insulation. It’s a good time to work through the rest of a seasonal plumbing maintenance checklist too.

Found a line that’s already frozen? Our prevent frozen pipes guide covers safe thawing. A line that has split needs an emergency repair before the water goes back on.

Conclusion

Winterizing home plumbing comes down to two paths. An occupied house needs insulation, steady heat, and drained outdoor faucets. A vacant house needs the main water valve off, every line drained, the water heater emptied, and RV antifreeze in the traps. Either way, start with the pipes in unheated spaces, because that’s where frozen pipes begin.

If you’d rather hand off the drain-down, All State Plumbing Pros can winterize the house for you. Our licensed and insured plumbers work throughout Fairfield County, CT, and Westchester County, NY, with water heater and well pump service, residential plumbing, and 24/7 emergency service. Reach our team to get on the schedule before the next cold snap, or explore our services from the All State Plumbing Pros homepage.

FAQs

How do you winterize your water pipes?

Shut off the main water valve, open every faucet from the top floor down, and drain at the lowest point. Then empty the toilets and water heater and add RV antifreeze to drain traps.

How to drain water pipes to keep from freezing in a home?

Turn off the main water supply, open all faucets and shower valves starting upstairs, and drain at the lowest faucet or drain valve. Flush the toilets, then blow out residual water with compressed air.

How to protect house pipes from freezing?

Insulate pipes in unheated spaces and on exterior walls, keep the heat steady day and night, and open sink cabinet doors. Let cold water drip from faucets on exposed pipes during very cold weather.

Do I need to drain my pipes for winter?

Drain your pipes if the house will sit empty for an extended stretch. If it stays heated and occupied, insulation, steady heat, and drained outdoor faucets usually do the job.

At what temperature do plumbing pipes freeze?

Pipes can freeze once water inside them drops to 32°F, and longer, colder spells raise the risk. Pipes in crawl spaces, garages, and exterior walls are most at risk.

How much does a plumber charge to winterize a house?

Angi puts the national average for winterizing a house at about $250, with a normal range of $65 to $1,000. Your price depends on house size, fixtures, and whether you have a well.