Conscious Choice: Efficient Water Heaters

May 2001 | Sensible Home

Efficient Water Heaters

by James Dulley

Dear Jim: I installed a new water heater, but it still takes forever for hot water to get to the bathroom faucets. It is annoying and wastes a lot of my time in the morning. What can I do to get hot water faster? — Sue H.

Dear Sue: You are not only wasting your time waiting for the hot water to arrive at the faucet, but you are wasting water, energy, and money. A typical family wastes forty gallons down the drain each day just waiting for hot water.

Installing a new high-efficiency water heater will not help at all, as you found out. The problem is the size of the plumbing and its layout. It just takes time for hot water to flow through the long maze of small pipes to a bathroom. To make things worse, it loses heat to the pipe along the way.

The best solution is to install one of several types of rapid-delivery hot water kits. There are various models made for retrofitting an existing home or for new home construction. After installing one kit, you should get hot water to all your faucets on that plumbing branch in less than fifteen seconds.

The most efficient and effective models use a demand design. When you get up in the morning, push a remote button on the wall to start the unit. New models also have motion sensors to start it automatically when you approach the vanity. These units use only about $1 of electricity per year.

The design concept is simple. A crossover valve, between the hot and cold water lines, is mounted under the sink. When you hit the demand button, a small high-volume, low-pressure pump starts drawing water from the hot water line, i.e., the water heater. It flows very fast through the pipes.

Instead of wasting this water down the drain, it flows through the crossover valve into the cold water pipe and eventually back to the water heater. When hot water reaches the sink, a sensor shuts off the pump and blocks the crossover valve. Open the faucet and you have steamy hot water.

Other kits use the same basic concept, but they operate by a timer instead of a demand button or motion sensor. A temperature sensor under the faucet turns the pump on whenever the water at the faucet cools down during the preset time periods. Early morning and late night are typical on-times.

You don’t have to be a plumber to install a rapid-delivery kit. All the parts are included, many with simple-to-install (no-soldering) fittings. Other simple low cost ($45), but less efficient, kits use only a crossover device. These rely on gravity, (hot water is less dense) to create the flow.

Still another simple method is to install a tiny point-of-use tank-type electric water heater under the sink. Put it on a timer to save electricity.

Write for (or instantly download) Update Bulletin No. 991, buyer’s guide of twelve manufacturers of demand/timer rapid-delivery hot water kits and point-of-use water heaters, controls, features, prices, and installation instructions. Please include $3.00 and a business-size SASE. James Dulley, Conscious Choice, 6906 Royalgreen Dr., Cincinnati, OH 45244.

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