In Ontario, where water heating accounts for 17.2% of the average Canadian home’s energy use (Natural Resources Canada, 2019), electric DHW heaters offer substantial environmental benefits, reducing greenhouse gas emissions by 80–88% compared to natural gas or oil. Compatible with Ontario’s low-carbon electricity grid and eligible for the Better Homes Peterborough Loan Program, these systems provide sustainable, cost-effective solutions.

Here’s a breakdown of three types—heat pump, tankless, and storage tank water heaters—detailing their features and benefits for Peterborough homeowners.

1) Heat Pump Water Heaters (HPWH)

Heat pump water heaters use electricity to transfer heat from the surrounding air to heat water, rather than generating heat directly. An ENERGY STAR certified heat pump water heater is up to four times more efficient and uses up to 70% less energy, on average, than a standard electrical water heater. Saving energy saves money and reduces your carbon footprint.

What to Look for:

• When choosing an HPWH, prioritize models with a high Energy Factor (EF) rating. An EF above 3.0 offers the greatest energy savings.
• Many models include smart controls for scheduling and hybrid modes that switch to electric resistance heating during peak demand, ensuring reliability.
• Ensure the unit suits your home’s space, as HPWHs require adequate air volume and perform best in temperatures above 5°C.

2) Tankless Water Heaters

Electric tankless models heat water as it flows, and only when required. They provide endless hot water, and the heat-on-demand feature means you only pay to heat water as you use it, instead of paying to keep a storage tank of water heated 24 hours a day, 365 days a year.

What to Look For:

• ENERGY STAR® certified tankless water heaters use 20-30% less energy, on average than heaters with storage tanks.
• Consider models with a 0.95 EF rating.
• Buy the right size for your needs. Consult an experienced plumber or HVAC contractor to estimate the hot water demands in your home.
• Confirm electrical capacity, as tankless heaters often require significant power (e.g., 240V circuits)

3) Electric Water Heaters with Storage Tank

Water heaters with storage tanks are the most common in Canadian homes, but they are not as efficient as heat pump or tankless models. Electricity is used to heat water stored in the tank and supply it, as needed, to household fixtures and appliances. Storage tanks typically hold between 113 and 378 litres of water in their tanks, and this water is continuously reheated and kept hot 24 hours a day.

What to Look For

• ENERGY STAR® certified models.
• Choose a water heater with the right storage capacity for your home and family.

Other considerations your water heater:

• Hire a certified HVAC technician to install the unit so that you are eligible for all warranties.
• Before you buy, check with your municipality or retailer to see if rebates are available.
• To improve efficiency, insulate the hot and cold-water pipes within 2 to 3 metres of the water heater.
• Have your unit serviced every year or two by a qualified professional. Consult your owner’s manual for details.
• For storage tank heaters, set the thermostat to 60°C to prevent Legionella bacteria growth, using a thermostatic mixing valve to deliver 49–50°C at taps for safety.

Source: Natural Resources Canada