Winterizing a Calgary home's plumbing takes an afternoon: shut off and drain hose bibs, blow out irrigation, test the sump pump, service the backwater valve, fix downspouts and find your main shut-off.
To winterize a Calgary home’s plumbing, do these nine things in the fall, before the deep freeze: shut off and drain every hose bib, blow out the irrigation system, protect pipes in the garage and crawlspace, test the sump pump, service a full-port backwater valve, point downspouts away from the house and clear of the sidewalk, flush the hot water tank, find and test your main shut-off, and check your insurance for sewer backup coverage. Most of it is homeowner work you can finish in an afternoon. The items that need a plumber can be booked at business-hours rates now instead of after-hours rates in January.
Here is the checklist, then the details for each item.
The Calgary fall plumbing checklist
| Task | Why it matters in Calgary | Who does it |
|---|---|---|
| Shut off and drain hose bibs | A hose left on can freeze and split the pipe inside the wall | Homeowner |
| Blow out irrigation | Water left in lines and valves splits them over winter | Homeowner or irrigation company |
| Protect garage and crawlspace pipes | The most common places for frozen pipes | Homeowner, plumber if pipes need rerouting |
| Test the sump pump | Spring melt and summer storms arrive on a full pit | Homeowner |
| Service the backwater valve | The City says full-port valves need servicing every year | Plumber, typically $150–$350 |
| Fix downspouts | Keeps water off the foundation and ice off the sidewalk | Homeowner |
| Flush the hot water tank | Calgary water is hard and scale builds in the tank | Homeowner or plumber |
| Find and test the main shut-off | You need it in the first minute of a burst pipe | Homeowner |
| Check insurance | Sewer backup coverage is optional | Homeowner and broker |
1. Hose bibs
Disconnect every garden hose. A hose left attached traps water in the tap, and the ice can split the pipe inside the wall where you will not see it until spring. If your hose bibs have an interior shut-off valve, close it, then open the outside tap to drain the line and leave it open. Frost-free hose bibs still need the hose removed to drain properly. If an outside tap dripped or sprayed inside the wall last spring, have it replaced before winter.
2. Irrigation
Shut off the irrigation supply at its valve and have the lines blown out with compressed air. Backflow devices and valve boxes hold water that will crack them over winter. Many homeowners hire this out. The plumbing part is making sure the supply valve inside the house is closed and not leaking.
3. Garage and crawlspace pipes
Pipes in an attached garage, a crawlspace or an exterior wall are where Calgary freezes happen. Keep the garage door closed during cold snaps, seal gaps where cold air reaches pipes, and add foam pipe insulation on exposed runs. If a crawlspace is unheated and has supply lines in it, talk to a plumber about whether those lines should be moved or better protected. Our guide to frozen pipes in Calgary covers where pipes freeze and how to thaw them safely.
4. Sump pump test
The City is clear that sump pump maintenance is the homeowner’s job and that the City does not respond to these calls. Test it now:
- Pour a bucket of water into the pit and confirm the pump starts, empties it and stops.
- Check the discharge. The City says discharge two metres from the foundation, and it must not flow onto neighbours, lanes, sidewalks, boulevards or streets, or back into the weeping tile.
- Follow the City’s advice: a backup pump powered by battery or generator (not a potable-water-powered backup), a check valve on the discharge, a high-water alarm, and replace the pump every 10 years or sooner.
Foundation drainage must not go into the sanitary sewer without a permit, except foundation drainage connected before 1973. If your pump hums, cycles constantly or is near the end of its life, a sump pump replacement typically runs $600 to $1,800 in 2026, before GST. Newer communities like Cranston and Auburn Bay are full of first-generation sump pumps worth checking.
5. Backwater valve service
The City’s guide says Alberta’s plumbing code requires below-grade fixtures to be protected from sewer backup from the street. If your home has a full-port backwater valve on the main sewer line, it needs servicing every year: open it, clean the flap and seat, check it seals. Branch valves on individual fixtures do not need the annual service. A backwater valve service or cleaning typically runs $150 to $350. See our backwater valve page for what a service includes, and our backwater valve guide for who needs one.
6. Downspouts
Two rules apply in Calgary:
- The Stormwater Bylaw says downspouts must not end within 2 m of a lane, street or sidewalk. The rule exists to prevent ice on sidewalks and lanes in winter. Downspouts must not connect to the weeping tile.
- The City’s flood-readiness page says eavestroughs and extensions should drain at least 1.5 m from the house.
Clean the eavestroughs after the leaves fall, make sure extensions are attached, and point them into your own yard. Water dumped against the foundation all fall ends up in the weeping tile and the sump pit.
7. Hot water tank flush
The City calls Calgary water hard. In 2025, hardness ranged from 141 to 200 mg/L as CaCO3 from the Bearspaw plant (north of the city) and 181 to 274 mg/L from the Glenmore plant (south), and it runs highest from December to February. Those minerals are why Calgary tanks build scale, run noisier and wear out sooner. Draining a few buckets from the drain valve at the bottom of the tank each fall clears some sediment. If the drain valve will not close properly afterward, or the tank rumbles, is leaking at the base or is near the end of its life, see our hot water tank repair page. Hot water tank repairs typically run $175 to $650.
8. Find and test your main shut-off
In most Calgary houses the main shut-off valve is in the basement, connected to the water meter. Find it now, clear anything stored in front of it, and make sure everyone in the house knows where it is. Turn it off and on once to confirm it moves. If it is seized or leaks at the stem, get it replaced during business hours. A shut-off that will not close during a burst pipe means waiting for a City service valve turn-off. Our guide on what to do when a pipe bursts explains why this valve matters so much.
While you are there, check the meter. It is City property, but protecting it from freezing is your responsibility, and the City charges $278.19 regular or $322.69 overtime/emergency for a frozen or damaged 15 mm meter in 2026. Keep that corner of the basement heated and close nearby windows.
9. Insurance check
Standard Canadian home policies typically cover sudden and accidental water damage from indoor plumbing. Sewer backup is typically not covered by a standard policy, though most insurers offer it as an option. Overland flood coverage is also optional and risk-based. Read your policy in the fall, not the morning after a storm, and ask your broker whether a backwater valve or sump pump changes your options.
When to call a plumber
If the checklist turns up a seized shut-off, a leaking hose bib, a backwater valve that has never been serviced or a tank that is past its best, book it now at business-hours rates. Plumbers in every part of the city, from SE Calgary to the northwest, get far busier once the first cold snap arrives.
FAQ
Common Questions
When should I winterize my plumbing in Calgary?
Do it in the fall, before the first hard freeze rather than after it. Calgary can see freezing nights early, and a hose bib or irrigation line with water in it can split on the first cold night. Pick a dry weekend, work through the outdoor items first (hose bibs, irrigation, downspouts), then the indoor ones (sump pump, backwater valve, hot water tank, main shut-off). Most of it is homeowner work. The backwater valve service and anything you are unsure about can go to a plumber during business hours.
How often does a backwater valve need servicing?
The City of Calgary's guide says full-port backwater valves, the kind installed on the main sewer line, need servicing every year. Branch valves on individual fixtures do not. A service means opening the valve, cleaning the flap and seat, and checking that it closes properly. In Calgary a backwater valve service or cleaning typically runs $150 to $350 in 2026, before GST. Fall is a good time because it is ready before spring melt and summer storms.
How far should my downspouts drain from the house?
Two rules apply. The City's flood-readiness advice says eavestroughs and extensions should drain at least 1.5 m from the house. Separately, the Stormwater Bylaw says downspouts must not end within 2 m of a lane, street or sidewalk, which prevents ice on public walkways in winter, and must not connect to the weeping tile. In practice, aim the extension away from the foundation and toward your own yard, well clear of the sidewalk and lane.
How do I test my sump pump?
Slowly pour a bucket of water into the sump pit until the float rises. The pump should start, empty the pit and shut off, and you should hear the check valve close. Then go outside and confirm the water is discharging onto your own property, about two metres from the foundation, not onto a neighbour, lane or sidewalk and not back toward the weeping tile. If the pump hums without pumping or runs without stopping, have it looked at before spring.
Does home insurance cover sewer backup in Calgary?
Usually not under a standard policy. Standard Canadian home policies typically cover sudden and accidental water damage from indoor plumbing, but sewer backup is typically an optional add-on, and most insurers offer it. Overland flood coverage is also optional and depends on your risk. The City of Calgary says the same thing: sewer backup, overland water and groundwater are optional coverages. Fall is a good time to read your policy and call your broker.
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