Conscious Choice: Super-Efficient Water Heaters

October 2001 | Sensible Home

Super-Efficient Water Heaters

by James Dulley

Dear Jim: Our old electric water heater does not leak yet, but we run out of hot water for morning showers. Would a new water heater help, and does it make economic sense to get a new one before the old one leaks? — Tom F.

Dear Tom: It is often wise to replace an old (ten years or more) water heater with a new super-efficient model. With new designs and better tank insulation, installing a slightly larger model to satisfy all your hot water needs will still cut down on your utility bills.

Older electric water heaters cost more to operate than most people realize. For a typical family of four, replacing an old model at a 0.80 EF (energy factor) with a new one at a 0.95 EF, saves about $100 per year. During its life, this compounds to more than $1,000. Some of the most efficient models also come with "no-leak" lifetime warranties. These models have a spherical top, instead of the typical flat top, to provide extra-thick insulation where the water is the hottest.

No-leak water heaters use all plastic and composite materials so there is no steel to rust near the water. The inner tank, made of tough, stable polybutylene, is wrapped with multiple layers of wound fiberglass for strength.

This inner assembly is then encapsulated in thick rigid foam insulation. The exterior shell is made of tough polyethylene plastic that resists dents and scratches. No anode rod is needed, so it does not create a water odor problem.

Some water heaters now include furnace-type setback clock thermostats that can use up to 15 percent less electricity. Others have new efficient electronic controls with four settings: normal, scald-resistant, energy-saver, and vacation/cabin. The normal setting allows for any water temperature.

To protect children and the elderly, the scald-resistant setting automatically adjusts the temperature. The energy-saver setting monitors your hot-water usage patterns and modifies the heating cycles, which results in lower utility bills. The vacation/cabin setting lowers the water temperature to 50 degrees to prevent freezing.

If space is limited and you cannot install a larger model, some new high-quality models offer 5,500-watt (3,800 or 4,500 watts is typical) heating elements. These powerful 5,500-watt elements provide more hot water quickly.

Most steel water heater tanks have a thin inner glass lining to stop corrosion. Another effective design uses a one-half-inch thick stone lining to extend the tank life. The stone also adds a little more insulation.

Especially if you have hard water, select a model with larger, hand-size sediment clean-out access holes. There are also special dip-tube designs that swirl the incoming cold water to keep sediment from building.

Write for (or instantly download) Update Bulletin No. 568, buyer’s guide of twelve manufacturers (fifty-five models) of super-efficient and no-leak electric water heaters listing water outputs, EFs, warranties, features, and a savings/payback chart. Please include $3.00 and business-size SASE. James Dulley, Conscious Choice, 6906 Royalgreen Dr., Cincinnati, OH 45244.

Recommend this page to a friend

Top Ten pages recommended to friends: