What winter home maintenance does a house in Toronto or Niagara actually need?

In Ontario, the winter problems that cost real money come from three places: water, gas and snow. Keep water from freezing in your pipes and out of your basement, keep the furnace and CO alarms working so carbon monoxide has nowhere to build up, and clear the sidewalk the way your city requires. Get these done before the first snow in November and most winter headaches never happen.

Yifei checking the eavestrough of a Niagara house in winter — After a snowfall, start by looking up: blocked eavestroughs and icicles are easy to spot from the driveway.

Why just these three

Shingles, window seals and paint wear out in winter too, but slowly; most of that can wait for spring. Water, gas and snow can't. A burst pipe or a wet basement ruins floors the same day. A furnace or vent problem is a safety issue. And an uncleared sidewalk can mean a city fine, or a slip-and-fall claim against the owner.

1. Water: don't let it freeze, don't let it in

Outdoor taps and exterior-wall pipes

Before the first hard frost, disconnect the garden hose. Water trapped in the tap freezes and can split the pipe inside the wall, and you won't see the leak until spring.
In older homes, shut the indoor valve for the outdoor tap, then open the tap outside to drain it. Frost-free taps still need the hose removed.
During cold snaps, open cabinet doors under sinks on exterior walls so warm air gets in.
Don't turn the heat off when you travel. If you'll be gone for several days, check your home insurance; many policies have conditions for unoccupied homes, such as regular check-ins.

Disconnecting a garden hose from an outdoor tap before the first frost — Disconnecting the hose is the cheapest winter maintenance there is.

Eavestroughs

Once the leaves are down, clean the eavestroughs. When they're clogged, meltwater refreezes at the roof edge and builds an ice dam that pushes water back under the shingles. Make sure downspouts send water away from the foundation. Have someone hold the ladder, or hire it out for tall or steep roofs.

Cleaning leaves out of an eavestrough while a helper holds the ladder — One cleaning after the leaves fall covers the whole winter.

Sump pump

Pour a bucket of water into the sump pit and make sure the pump kicks on and clears it. The real test comes with the spring melt. Yifei's own basement flooded once because the pump couldn't keep up. Ask a plumber whether a battery backup or high-water alarm makes sense for your house.

2. Gas: keep the furnace healthy and CO going outside

Furnace filter: Canada's DND housing handbook suggests checking the filter monthly and replacing it about every three months, more often with pets or renovations.
Annual inspection: TSSA recommends having fuel-burning appliances inspected every year by a TSSA-registered contractor, and says poor maintenance is the leading cause of home CO incidents.
CO alarms: Under Ontario rules, homes with a fuel-burning appliance, a fireplace or an attached garage need CO alarms outside each sleeping area, and since January 1, 2026, on every storey, including storeys without bedrooms. Ontario advises testing monthly, replacing batteries yearly, and replacing the alarm per the manufacturer.
Meter and vents: Enbridge reminds customers to clear snow from the gas meter and appliance exhaust vents after every storm, using a soft broom, never a shovel. Blocked vents can push carbon monoxide back into the house.
Humidity: Health Canada recommends keeping indoor relative humidity between 30% and 50%. Daily condensation on windows usually means it's too high. Run the bathroom fan 30 minutes after showers.
Radon: Health Canada recommends a long-term test of at least 3 months on the lowest lived-in level, ideally in fall or winter. Take action at 200 Bq/m³ or above.

Replacing a furnace air filter in a basement — Hold the old filter up to the light; if none gets through, replace it.

Pressing the test button on a carbon monoxide alarm outside a bedroom — One outside the bedrooms, one on every storey, tested monthly.

Condensation on a winter window with a humidity monitor on the sill — Water on the glass every morning means the air is too humid.

3. Snow: the sidewalk in front is the owner's job

Rules differ by city, so check yours. Two examples:

St. Catharines: owners must clear the sidewalk at the front, side and rear of the property to bare pavement within 24 hours of a snow or ice event; fines are charged per metre not cleared. Owners with physical limitations can apply for city help.
Toronto: the city clears most sidewalks mechanically; when snowfall is under 2 cm, residents and businesses must clear the sidewalk within 12 hours after the snow stops.

Salt or sand icy steps, knock down large icicles over doors and the gas meter, and remember that a slip on your property can lead to a claim against you; check your policy.

Shovelling a driveway and sidewalk after snowfall with a bucket of salt nearby — Clear to bare pavement once the snow stops, then salt the steps.

Winter maintenance checklist

Grouped by timing. Tap to tick items off as you go; your phone remembers where you left off.

November, before the freeze

December to February, monthly

Check the filter
test CO alarms
watch window condensation
start a radon test

After every big snowfall

Clear the sidewalk and driveway
brush off the gas meter and vents
knock down icicles

Away for several days

Leave the heat on
arrange check-ins
read your insurance conditions

March thaw

Test the sump pump again
look for new water marks in the basement

Selling this winter?

Buyers and home inspectors look at the same things: furnace age and service records, water marks in the basement, and whether the CO alarms are all there. Keep your receipts. For timing, see Should I wait until spring to sell in Niagara?

Frequently asked questions

Do Ontario homes have to have carbon monoxide alarms?

Yes, if the home has a fuel-burning appliance, a fireplace or an attached garage: outside each sleeping area, and since January 1, 2026, on every storey.

What indoor humidity is right in winter?

Health Canada recommends 30% to 50% relative humidity indoors.

How fast do I have to clear my sidewalk in St. Catharines?

Within 24 hours of a snow or ice event, to bare pavement, at the front, side and rear of the property. In Toronto, within 12 hours when snowfall is under 2 cm.

When is the best time to test for radon?

Fall or winter, with a long-term test of at least 3 months on the lowest lived-in level.

In one line

Handle water, gas and snow first; everything else can wait for spring.

Want advice for your own house?

The age of the house, whether it has a basement and what kind of furnace it runs all change the list. For your own situation, reach Yifei (RE/MAX) at efay.ai.

Sources

Ontario, carbon monoxide safety: https://www.ontario.ca/cosafety
Health Canada, moisture and mould: https://www.canada.ca/en/health-canada/services/publications/healthy-living/addressing-moisture-mould-your-home.html
Health Canada, long-term radon test: https://www.canada.ca/en/health-canada/services/publications/health-risks-safety/radon-long-term-test-instructions.html
DND housing handbook, indoor air quality: https://www.canada.ca/en/department-national-defence/services/benefits-military/military-housing/occupant-handbook/air-quality.html
TSSA, carbon monoxide: https://www.tssa.org/carbon-monoxide-silent-killer-what-ontarians-need-know-winter
Enbridge, keep meters and vents clear: https://enbridgegas.mediaroom.com/2025-02-14-PUBLIC-SERVICE-ANNOUNCEMENT-Enbridge-Gas-Reminds-Customers-to-Keep-Gas-Meters-and-Vents-Clear-of-Ice-and-Snow
St. Catharines, sidewalk snow removal: https://www.stcatharines.ca/roads-parking-and-traffic/snow-removal/sidewalk-snow-removal/
Toronto, sidewalk clearing: https://www.toronto.ca/services-payments/streets-parking-transportation/road-maintenance/winter-maintenance/sidewalk-clearing/

Yifei Lin is a RE/MAX real estate agent serving the Greater Toronto Area and Niagara since 2015. For advice on your own situation, reach him at efay.ai.

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