Prolonged power outage

The following information was taken from the Canada Mortgage and Housing Corporation (CMHC) site.


When You Must Leave Your House Due to a Prolonged Winter Power Outage

In the winter, the power supply to your home can be interrupted from a few hours to several days by freezing rain, sleet, snow storms and/or high winds which damage power lines and equipment. This is the same power supply that you need to heat your home, be it electric baseboards or furnaces, or gas or oil furnaces (which use electric controls and distribution fans). If you encounter an extended period of time without power, the result can be a loss of heating, which in turn results in a cold home, severe living conditions, and possible damage to walls, floors and plumbing.

Be Prepared

During a winter power outage, you should be prepared to follow some procedures to help protect your home from damage. You should have a power outage preparedness plan that includes listing the location of your electrical breakers, gas and water valves. Everyone in your household should know where this document is kept. In advance, you should also consider the following:

Keep spare batteries, along with a readily accessible flashlight and portable am/fm radio.

Keep handy extra fuses (if you have an electrical box that uses fuses).

If your home is prone to flooding, consider purchasing and installing a DC sump pump and back-up battery, or a properly sized inverter and battery for the pump.

Prepare a 3-day, emergency kit which includes: 4 litres of water per person/day, canned food, a manual can opener, utensils, a sleeping bag or blanket per person, medication, flashlight, a crank or battery operated radio, spare batteries, a change of clothes, diapers, a first aid kit, insurance information and if applicable, pet food and litter. Pack all of these items in a bag — also refer to emergency preparedness websites or the emergency section of your phone directory.

Routinely check your main water supply valve to ensure proper operation.

Leaving Your Home

If you must leave your home for more than 24 hours because of a power failure, here are some simple things to do to prevent house damage.

Electricity and Power

  • Shut off power to house at breaker box.
  • Shut power off at the breaker to the water heater, furnace, water pump (if you have one) and sump pump.
  • Make sure that appliances, electronic equipment and tools are turned off at the switch and unplugged.
  • Close gas valves, if you have natural gas or propane.
  • Unplug major appliances so that they do not start up cold when power is restored.
  • Turn the thermostat down.
  • Use a flashlight versus candles or oil lamps.


  • Turn off water supply at water service entrance (the valve is generally located at the front of the house, near the basement floor).
  • Open all taps, starting at the top of the house and let them drain. Flush the toilet to drain the tank. If you get your water from a well, drain the pump line and expansion tanks. Unhook washing machine hoses and drain. Leave all taps open while you are gone.
  • If you are not on a septic system and have to leave for a long period and freezing is certain, pour a non-toxic antifreeze (cottage or recreational vehicle antifreeze, or windshield washer fluid) in all traps (toilets, sinks, washing machines, showers). Caution: Never add an ammonia-based product to items that have the non-toxic antifreeze in the trap — such as for cleaning the toilet bowl before you leave. The results are hazardous.
  • If the temperature inside your house will remain below freezing for a long time, turn off power source first and then drain the hot water tank by attaching a hose to the tank drain valve and running it to the basement floor drain. For electric hot water tanks, turn off the power at the breaker. For gas hot water tanks, turn the gas valve to “OFF”.
  • If the weather is not too cold, or if you are checking the house regularly, the hot water tank may survive without draining. In this case, turn off the power to the hot water tank at the breaker or fuse box, or turn the gas valve to “Pilot”.
  • If your house is equipped with a sump pump to protect it from ground water, it will not work without electric power. Consider a back-up power source.
  • If your home is on a septic system, do not use excessive water as the aeration pump or lift pump will not be operational.
  • Wrap any exposed water pipes with insulation.
  • Move valuables off the basement floor in case there is flooding.

 More Tips

For prolonged departures, pile snow, straw or other insulation material around the basement walls to prevent soil freezing next to the foundation. Close the door to the basement to keep in the heat.

Empty refrigerators and freezers. If possible, do not keep surplus food. Wedge freezer and refrigerator doors open to prevent mold growth. Ensure that the devices used to hold the doors open cannot trap a child or pet inside.

Notify municipal authorities — police, fire, hydro — that you are leaving the house. Unless there is a life or property-threatening emergency (illness or powerline down), do not call 9-1-1. Use the numbers specified in your phone directory.

If you have a pet, ask your vet where you can take a pet during an evacuation.

Take proof of identification with you.

Ensure your home is secure before you leave, and bring your house key (doors and windows closed and locked).

If you rely on your garage door opener for access to your garage, be sure you know how to operate it manually to access your car.

 Returning Home

Power and Energy

  • Use a flashlight — don’t light matches or turn on electrical switches if you suspect damage or smell gas.
  • Do not start major appliances until the house has returned to near normal temperature.
  • Ensure that stoves, ovens, washing machines, electronics and portable space heaters are turned off at the switch.
  • Turn on power to the house breaker box — with all appliances still unplugged.
  • Turn power on to individual appliances (including refrigerators and freezers) when they are warmed up.
  • If you turned off the gas, it should only be turned back on by a professional from the gas company.
  • If there is flooding, do not operate appliances, electrical outlets, switches or fuse-breaker panels until they have been checked and serviced by a qualified technician.


  • Do not turn on the house water supply until indoor air returns to near normal temperature — in the 20oC range.
  • Close all open taps, close hot water tank drain, reconnect washing machine hoses and the drain.
  • Turn on water at water service entrance.
  • Ensure that hot water taps are running and that the hot water tank is full before turning it on. Electric hot water tanks can be turned on at a breaker. If you have a gas hot water tank, call a service person to restore the gas to the tank.
  • Turn on the tap which is on the highest level in the house until water is flowing, to bleed air out of the system. Ensure that drains are not clogged with ice or cracked by freezing. Run other taps until water is flowing. Check for leakage from pipes where possible. If you find leaks, turn off the water supply to the leaky pipe or turn off water at the service entrance until leaks are repaired.
  • If you are on a septic system, do not add antifreeze, salt or additives to the septic tank and do not run the water continuously to unfreeze the system. Many contractors have pressure steamers to defrost frozen piping or can install heat tape or a tank heater.
  • Check sump and sump pipes for freezing before starting the sump pump.
  • If there is flooding in the basement, drain the water in stages, about a third of the volume of water per day. Draining the water too quickly can structurally damage your home. CMHC’s booklet — “Cleaning Up Your House After a Flood” — contains useful information. You can obtain it from your local CMHC office or by calling 1 800 668-2642.

 More Tips

  • Do not use an open flame to thaw frozen pipes.
  • Confine or secure your pets until the house is deemed safe.