Tankless Water Heaters:  One-Two Punch

• Rinnai

• Dimensions: 18-1/2" wide x 26-1/2" high x 10" deep
• Energy Star certified
• 12 year warranty on heat exchangers, 5 on other parts
• Heats 9.8 gallons per minute

• Online range of $1,300 to $2,000.
• Pricing as of 2011.

• RC98i

• Get Rinnai contact information plus see product stories we've published about the company.

The RC98i heater achieves an impressive 96 percent efficiency rating by using two exchangers in the heating process. A stainless steel condenser uses ambient air to warm water flowing into the system. A high-powered copper heat exchanger then quickly brings the water to full temperature.

By comparison, a quick survey of 40 and 50 gallon storage tank style propane heaters shows efficiency ratings of 56 to 62 percent.

So what's not to like about saving energy while never having to worry about your shower going cold?

The price may be one thing. The lowest price we could find for this propane or natural gas heater was about $1,300. Compare that to $325 for a brand-name tank-style electric heater. How quickly you can recoup that higher initial investment through energy savings depends hot water consumption and whether natural gas or much more expensive propane is available in your area. But if you've decided that tankless is the way to go, Rinnai's heater is one to consider.