How to Winterize Your Plumbing for a Chicago Winter

Prevention: outside the house

The discharge line deserves a second look every year. A line that freezes at the outlet leaves the pump running against a blocked pipe, which ends pumps early and floods basements during a February thaw.

• Disconnect every garden hose — a connected hose traps water in the bib and is the single most common cause of a split
• Shut the interior stop for each hose bib if you have one, then open the outside spigot to drain it
• Add insulated faucet covers on bibs that are not frost-free
• Check that the sump pump discharge terminates well away from the foundation and does not sit in a low spot that can ice over
• Clear leaves from window wells and grade so meltwater runs away from the house
• Shut off and drain irrigation systems according to the manufacturer's procedure

More on how that failure shortens pump life is in our guide to sump pump life expectancy.

Prevention: inside the house

A steady thermostat matters more than most people expect. Deep overnight setbacks save a little on gas and cost far more when a kitchen line on an exterior north wall gives out.

• Insulate pipes in crawl spaces, unheated garages, attics and along exterior walls
• Close crawl space vents and seal obvious drafts near pipe runs
• Find and label your main shutoff, and make sure the valve actually turns
• Open vanity and sink cabinets on exterior walls during a deep freeze so room heat reaches the pipes
• Keep the thermostat at a steady temperature rather than deep setbacks overnight in extreme cold
• Check the water heater for corrosion at fittings and confirm the relief valve discharge pipe is intact

Prevention: heating equipment that protects the plumbing

A plumbing winterization plan should include the heating equipment that protects vulnerable pipe runs. A furnace, boiler or thermostat problem can allow exterior-wall, crawl-space and utility-room temperatures to fall far enough for piping to freeze. A fall heating check can identify ignition, combustion, circulation, airflow and control problems before sustained cold weather.

Your pipes depend on the heat staying on. If the furnace or boiler cannot keep the building warm, plumbing in cold parts of the house can freeze even if the pipes themselves were fine before. Testing the heating system now gives you time to repair a problem before a freeze.

Furnace, boiler and thermostat work is on our heating services page, and the repair-or-replace thresholds we use are in

signs your furnace needs repair vs. replacement.

Winterizing an occupied home is different from draining an empty property

An occupied home usually needs reliable heat, protection for vulnerable water lines and a plan for a power or heating failure. An empty property with the heat off may need its water system professionally shut down and drained. Closing the main valve alone does not empty branch piping, water heaters, appliances or fixtures.

Before travel, arrange for someone to check the building and respond to an alarm. A remote temperature sensor can help identify a change, but it depends on its power, connection and alert settings. Ask the person checking the house to look for water and confirm heat near vulnerable rooms, not only read the hallway thermostat.

If a property will lose heat, discuss its actual plumbing layout before choosing a shutdown procedure. Boiler and hydronic heating circuits are separate from domestic water lines; do not drain them, add automotive antifreeze or close unfamiliar valves as a general winterization step. Equipment and appliance shutdown should follow the manufacturer's instructions.

Our plumbing and HVAC system inspections can help identify accessible concerns and needed follow-up; it does not certify concealed piping or guarantee freeze protection.

For the decision about isolating domestic water, read when to shut off water before a Chicago freeze. A shutdown plan still depends on the installed equipment.

Little or no water during a freeze: when to stop and call

Check whether the problem affects one fixture or the whole property, and note any visible leak. If water is escaping, close the main shutoff only when it is safe to reach. Stay out of standing water near electrical equipment and do not use electrical thawing devices in a wet area.

Never use an open flame or torch. If the frozen section is hidden, inaccessible, visibly damaged or close to electrical equipment, stop and call a plumber. A frozen pipe can already be split, with the leak becoming apparent only as the ice melts. Do not cut into walls or force a stuck shutoff as a quick fix.

Tell us which fixtures have lost flow, whether the heat is operating and whether water is visible.

For active diagnosis and repair, use our frozen-pipe repair page. After the immediate problem is handled, review drafts, insulation and the pipe route so the same location is not left exposed.

If a frozen pipe has already split and water is running, our emergency plumber Des Plaines page covers what we respond to and how to reach us right away.

Frequently asked questions