Water Heating


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Heating your water is likely the second-largest utility expense in your home. Here are some water heating tips that can lower your monthly water bill.

  • Turn down the thermostat on your water heater
  • Install a timer that automatically turns the hot water off at night and on in the morning.
  • Install a heat trap, a simple piping arrangement that prevents hot water from rising up in the pipes, to help minimize losses.
  • Drain a quart of water from your hot water tank every 3 months. This removes sediment that prevents heat transfer and lowers the unit's efficiency.
  • Insulate your water heater

Insulating Your Hot Water Heater

Water heaters consume much of their energy just keeping a supply of hot water ready and waiting in the tank. Heat gradually leaks out of the tank, and then it must turn on again to reheat the water. To minimize this heat loss from your water tank, insulate it using a ready-made kit. They are available at most hardware and building supply stores.

CAUTION: Be careful not to cover the thermostat when insulating your water heater and always follow manufacturer's instructions.

Buying a New Water Heater

When buying a new hot water heater there are two important things to think about: The Energy Factor (EF) and the First-Hour Rating (FHR).

  • Energy Factor (EF)
    The efficiency of water heaters is indicated by their energy factor (EF), which is based on recovery efficiency, standby losses, and cycling losses. Water heaters with a higher EF are more efficient. Electric resistance water heaters have EFs ranging from 0.7 and 0.95. Gas water heaters range from 0.5 and 0.6, with some high-efficiency models ranging around 0.8. Oil water heaters range from 0.7 and 0.85, and heat pump water heaters range from 1.5 to 2.0, making them an efficient choice.
  • First-Hour Rating (FHR)
    Some consumers buy water heaters based on the size of the storage tank, but the first-hour rating (FHR), provided on the EnergyGuide label, is actually more important. The FHR is a measure of how much hot water the heater will deliver during a busy hour. Before you buy a water heater, estimate your household's peak-hour hot water use (ex. your water use during morning showers) and look for a unit with an FHR in that range.
In Canada, all water heaters are sold with EnergyGuide labels to indicate their energy efficiency. These labels show estimated annual operating costs, and the cost of operating the models with the highest annual operating cost and the lowest. By comparing a model's annual operating cost with the operating cost of the most efficient model, it’s easy to check its efficiency.