What's the most energy efficient water heater?

Tankless (on-demand) water heaters are generally the most energy-efficient option available today, using 20-40% less energy than traditional tank water heaters for most households.

Why Tankless Wins on Efficiency

Traditional tank water heaters keep 40-60 gallons of water hot 24/7, constantly burning energy even when you're at work or sleeping — this is called standby heat loss. Tankless units eliminate this entirely by heating water only when you turn on a tap. A quality tankless unit like a Navien, Rinnai, or Noritz can achieve efficiency ratings of 94-99% (AFUE), compared to 60-80% for older tank models.

Heat Pump Water Heaters: The Hidden Champion

If you have space in a conditioned area (basement, utility room), a heat pump water heater (HPWH) is actually the most efficient option of all — 3-4x more efficient than a standard electric tank. They work by pulling heat from surrounding air rather than generating it directly. The tradeoff is a higher upfront cost and they need adequate space (roughly 1,000 cubic feet of air volume around them).

Ottawa-Specific Considerations

Ottawa's cold winters are worth factoring in. Gas tankless units tend to be the most popular choice here because natural gas rates are generally lower than electricity, and they perform reliably in cold climates. Heat pump water heaters can lose some efficiency in very cold spaces, so your basement temperature matters. A licensed plumber can assess your home's setup — gas line capacity, venting requirements, and electrical panel — before recommending the right unit.

Rebates Available

Check Enbridge Gas and Canada Greener Homes rebates before purchasing — tankless and heat pump water heaters often qualify for significant rebates that offset the higher upfront cost.

In Ottawa, expect to pay $3,500 - $5,500 installed for a tankless unit, or $1,500 - $2,500 for a high-efficiency tank replacement. The tankless premium typically pays back in 5-8 years through energy savings.

For a free consultation on which water heater makes sense for your home, reach out to Ottawa Pro Plumbing — we can assess your current setup and walk you through the best options.