How to keep pipes from freezing when you are away, at the cottage or without power

01 /Why do pipes freeze in empty houses?

Pipes in an empty house freeze because the protections an occupied house gets for free disappear. Nobody runs water, so every line sits still. Nobody notices the furnace has stopped, a breaker has tripped or the power has been out for a day. Thermostats get turned down to save money, and cabinet doors stay shut. A small problem that a resident would catch in an hour runs for days.

It is also the situation insurers treat most strictly. The Insurance Bureau of Canada explains that standard home policies generally cover damage from freezing and burst pipes when the pipes are in the heated part of the home and reasonable steps are taken to keep the heat on, that most policies require a competent person to check a home at a set frequency while you are away, and that freezing damage in a vacant home is typically excluded. Read your own policy's wording before a trip, not after.

02 /What should I do before a winter trip of a few days to a few weeks?

1. Keep the heat on at a safe floor

   Calgary asks residents to keep the thermostat at least 15 °C; Winnipeg says no lower than 12 °C when away. Set it at or above your utility's number, and higher if you know a pipe runs cold.

2. Open cabinet doors on exterior walls

   Kitchen, bathroom and laundry cabinets let room heat reach the supply lines. Leave interior doors open so heat reaches every room with plumbing.

3. Shut off and drain outdoor taps

   Disconnect hoses and drain the hose bib lines, as the outdoor tap guide describes.

4. Close the main water valve

   Toronto advises closing the main valve that supplies your internal plumbing when away for an extended period, and draining the remaining water. Even without draining, a closed main limits a split to the water already in the pipes.

5. Arrange checks

   Ask someone to walk through the house at the interval your insurer requires, checking the thermostat, the furnace, the sink cabinets and any spot that has frozen before.

6. Add a remote alert

   A low-temperature alarm or connected thermometer that sends a phone alert below a set point, such as 7 °C, gives a warning if the heat fails.

03 /How do I winterize a vacant house or a cottage?

For a house that will sit unheated, or with heat you cannot rely on, remove the water instead of trying to keep it warm. The steps below are the general pattern; a plumber can do it, and many cottage owners hire the same person to open the place in spring.

1. Shut off the supply. Close the main valve, or for a well, turn off the pump at its breaker. For a lake intake, follow the setup's own procedure for draining or pulling the line.
2. Turn off the water heater first. Switch off the power or set a gas heater to its vacation or off setting before draining, and let the water cool. Then drain it with a hose from the drain valve to a floor drain or outside.
3. Open every tap, top to bottom. Open all hot and cold taps, starting upstairs, then open the lowest tap or drain valve in the basement to let the system empty.
4. Flush and empty the toilets. Flush with the water off, then sponge or pump out what remains in the tank and bowl.
5. Drain the appliances. Disconnect and drain washing machine hoses; follow the dishwasher, softener, filter and ice maker instructions for winter storage.
6. Blow out the lines if needed. Low spots can hold water; a plumber may blow the lines out with compressed air.
7. Protect the traps. Pour non-toxic plumbing antifreeze, made for potable systems and not automotive antifreeze, into sink, tub and shower traps, floor drains and toilet bowls so the seals do not freeze and crack.
8. Leave taps open and label everything. Open taps give leftover water room, and a tag on the main valve reminds the next person the system is drained.

Well systems add a pressure tank and pump to drain, and seasonal properties may have pipes under a floor that are hard to empty completely. Local cottage plumbers know the common setups in their area; request quotes if you want the job done or checked.

04 /How do I keep pipes from freezing in a power outage?

In a winter outage the house cools gradually, and how long you have depends on insulation, outdoor cold and wind. The Government of Canada's Get Prepared guidance for power outages says to learn how to shut off the water system and to drain water from your plumbing because pipes can freeze during winter outages. The Insurance Bureau of Canada gives the same advice for a heating breakdown: shut off the water and drain the pipes if the heat cannot be restored, and use safe alternative heat in the meantime.

Get Prepared also points out a detail that protects the water heater: make sure it is filled before turning its power back on. Heating an empty electric tank can burn out its elements.

05 /What if the heat is on but the house is empty for the winter?

Some owners keep a vacant house heated, for example while it is for sale or between tenants. That protects interior plumbing, but the risks move to the spots heat does not reach: exterior-wall sinks behind closed cabinets, a garage line and any pipe that has frozen before. A furnace failure also has days to do damage between checks.

• Keep the thermostat at or above your utility's floor, and keep cabinet doors and interior doors open.
• Shut off the main between visits and drain the lines if the house will not be used, even though the heat stays on.
• Fit remote temperature alerts in the coldest spots, not only beside the thermostat.
• Check the policy's vacancy wording with your insurer; the obligations can differ from an occupied home.
• Book a furnace check before winter, and leave the service number where the checker can see it.

06 /How do I bring the water back after winter?

Turn it back on slowly and watch. Close the drain valves and the taps you left open, make sure the water heater is full before it is powered, then open the main a quarter turn at a time while someone listens and looks around the house. Open taps one at a time to let air out. Check under sinks, around the water heater, near outdoor taps and along any line that has frozen before.

Then check the meter's leak indicator with everything off. A moving dial means water is going somewhere; close the main and find it before it finds the ceiling. If a split has flooded anything, the incident steps are on BurstPipe.ca.

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