Hot Water on Demand System Saves Energy

QUESTION: I let the water run for over a minute just to get hot water from one of the bathroom faucets. This wastes my time and a lot of water down the drain. Is there any do-it-yourself gadget to get hot water faster?

ANSWER: In the typical U.S. home, more than 9,000 gallons of water are wasted down the drain each year waiting for hot water. In addition to wasting water and your time in the morning, it causes an indirect energy loss that pushes up your gas and electric bills too.

The energy loss can be as high as 15% of your annual water heating costs. In the winter, all the room temperature water that runs down the drain is replaced by cold incoming water from the city main. Your furnace and water heater must run longer just to warm that extra 9,000 gallons of cold water.

The newest and most efficient instant hot water system uses a demand triggered design. It is ideal for an existing home and you can easily install it yourself in two hours.

This simple hot water demand system uses a tiny high volume pump located under the bathroom sink farthest from the water heater. This pump and a solenoid valve connect the hot and cold water lines under the sink.

When you want hot water, turn any hot water faucet on and off quickly. This triggers the pump to start running. It rapidly draws water from the hot water pipe under the sink and diverts through the solenoid valve back to the water heater via the cold water inlet line-all through existing plumbing.

Within seconds, the hot water reaches the sink. As soon as a sensor detects the hot water at the sink line, the pump shuts off and you turn on the hot water faucet. Any faucet you turn on triggers the pump to start. If you mount this pump under the sink farthest from the water heater, you will have instant hot water at all your faucets.

Another option, installing a special continuous hot water circulation pump, requires adding a return pipe from the sink to the water heater. This is simplest in new construction, but you can also add it in an existing home. You can run the return water pipes from floor to floor through closets.

Although this wastes some energy by continuously circulating hot water in the pipes, you can minimize this loss by insulating the pipes. Installing a circulation pump with a 24-hour timer also reduces losses. You can set it to run only during the times of the day when you use hot water the most.

Installing an inexpensive 115-volt electric tankless water heater under the sink also provides instant hot water. The plumbing hookup is very simple.

Write for Utility Bills Update No. 733 listing manufacturers of hot water demand systems, continuous circulation pump/timer and electric tankless water heaters, prices, specifications and a chart showing daily hot water needs. Please include $2 handling fee--cash or check. Send your requests to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.

Can Electric Meter Give Wrong Reading?

Q: Last summer, with no lights on and the refrigerator not running, I noticed that the wheel in my electric meter was still spinning pretty fast. Could the meter be bad and recording too much usage?

A: Although it is possible that the electric meter is wrong, it is unlikely. A modern home uses electricity even when nothing is turned on.

The refrigerator could be in the auto-defrost mode, which consumes much electricity.