Winterizing a Home: Pipes, Drafts and Heating

Before you read the rest of this guide, go find your main water shutoff valve. In many homes it's where the water line comes through the foundation, in a basement, crawlspace, utility closet or garage. In some warmer regions it sits outside, near the meter or in a small box in the ground. Turn it off and back on once to make sure it isn't seized, and show everyone in the house where it is. If a pipe bursts on a January night, the time it takes to find that valve decides how much water ends up on the floor.

With that done, winterizing comes down to three things: keeping the water in your pipes from freezing, keeping cold air on the outside of the walls and keeping the heating system running safely until spring.

Pipes: where freezes happen and how to prevent them

Pipes freeze where cold air reaches them. Think crawlspaces, unheated garages, attics, exterior walls, and cabinets under sinks that sit against an outside wall. Pipes near foundation vents, dryer vents and gaps around the sill are especially exposed, since moving air pulls heat away faster than still air.

Start by sealing the gaps. Caulk or foam the openings where pipes and wires pass through exterior walls, and close any foundation vents that your home's design and local practice call for closing in winter. Then insulate exposed pipes you can reach with foam pipe sleeves, paying extra attention to corners and fittings.

For pipes that stay at risk, electric heat cable can help. Use only products listed for the purpose, follow the installation instructions exactly and never overlap the cable unless the maker allows it. If you're not comfortable with it, an electrician or plumber can install it.

On very cold nights, a few simple habits help:

• Open cabinet doors under sinks on exterior walls so room heat can reach the pipes
• Let a faucet on a vulnerable line drip slightly, since moving water is harder to freeze
• Keep the garage door closed if water lines run through the garage
• Hold the thermostat at a steady setting day and night instead of letting it drop sharply

If a pipe freezes anyway

A faucet that barely trickles or gives nothing at all on a frigid morning may have a frozen line. Leave the faucet open, since flowing water helps melt the ice once thawing starts, and apply gentle heat to the section you suspect: a hair dryer, a space heater set a safe distance away, or warm towels. Never use an open flame or a torch. Keep electrical devices away from any standing water.

If you can't find or reach the frozen section, call a plumber. And if a pipe has already split, shut off the main water valve immediately, then call. If water is near outlets, fixtures or the electrical panel, stay clear and call an electrician or your utility before touching anything.

Drafts: finding the leaks you can feel

On a windy day, walk along the inside of your exterior walls with a lit incense stick or a damp hand. Where the smoke wavers or your hand feels a chill, you've found a leak. Common culprits include door edges, window sashes, electrical outlets and switch plates on exterior walls, baseboards, the attic hatch and the fireplace.

Most fixes are inexpensive and easy:

• Replace worn or flattened weatherstripping on doors and windows
• Add a door sweep if you can see light under an exterior door
• Install foam gaskets behind outlet and switch covers on exterior walls
• Weatherstrip and insulate the attic hatch or pull-down stairs
• Close the fireplace damper whenever the fireplace isn't in use and the fire is fully out
• Use removable window insulation kits on drafty single-pane windows

Bigger problems, such as thin attic insulation or leaky ductwork running through unheated spaces, are worth an energy assessment. Some utilities offer these, and a qualified contractor can tell you what makes sense for your house and climate.

Heating: running safely all winter

Your heating system does the heavy lifting for months, so start the season with a fresh filter and check it monthly. Keep supply vents and return grilles clear of furniture and rugs.

If you have a high-efficiency furnace or water heater, find where its plastic vent pipes exit the house. After snowstorms, keep those openings clear of snow and ice, since a blocked vent can shut the system down or push exhaust back inside.

Space heaters need space. Keep them well away from curtains, bedding and furniture, plug them directly into a wall outlet rather than an extension cord, and turn them off when you leave the room or go to sleep. Choose models with tip-over and overheat shutoff features.

Carbon monoxide detectors matter most in winter. Test them, replace batteries as needed, and make sure there's one on each level and near sleeping areas, or wherever your local code requires them.

If you smell gas, don't flip switches or use your phone inside. Leave the house and call the gas utility or 911 from outside.

If you'll be away for a while

A house left alone in winter needs a plan. Keep the heat on at a moderate setting rather than turning it way down. Many plumbers suggest not letting it fall much below the mid-50s Fahrenheit, but ask one about your particular home. Leave cabinet doors open under sinks on exterior walls.

For longer trips, consider shutting off the main water valve and draining the lines by opening faucets at the lowest point in the house. Ask a trusted neighbor or friend to check on the house periodically, look for signs of heat loss and call you if something seems off. Some homeowners also use a temperature sensor that sends a phone notification if the house gets too cold.

Questions to ask at your heating tune-up

A technician's visit is a good chance to learn about your system. Consider asking:

• Is the heat exchanger in good condition, and did you check it for cracks or corrosion?
• Are the venting and flue connections sound and properly sloped?
• Which filter size and type do you recommend for my system?
• Is my thermostat placed well, or is it reading a cold or warm spot?
• Are there parts showing wear that I should plan and budget for?
• What sounds or smells should prompt me to call before the next visit?
• Does anything about my ductwork or insulation stand out?

Write the answers down and keep them with the system's manual.

Keeping winter in its place

Winterizing isn't a single weekend. It's a few habits you carry from the first cold night to the last. For the seasons on either side, HomeIsSecure's homeowner guides include fall prep and a spring checklist. As always, codes, permits and licensing rules vary by state and city, and gas, electrical and heating equipment work belongs with licensed professionals.