Oh, for a Hot Shower Any Time

QUESTION: I like a steamy hot shower in the morning, but we run out of hot water after the kids’ showers. Keeping the water heater temperature set high wastes energy. Will a new instantaneous tankless water heater help?

ANSWER: An instantaneous water heater is the most energy-efficient option available. It can supply enough steamy water for 10 consecutive showers in the morning, yet use much less energy than your current water heater. A standard tank-type electric water heater easily can account for $200 to $300 of your annual utility bills.

With an instantaneous water heater, you can immediately run your dishwasher or clothes washer after showering without having to wait for the water in the tank to heat again. Standard water heaters, especially electric, have slow heat recovery rates.

To supply enough hot water for many showers with a typical water heater, you either must set the water temperature very high or have a very large capacity tank. The tank walls continually lose about 15% of the heat. This increases your utility bills year-round and the load on your air conditioner in the summer.

An instantaneous (also called tankless) water heater has no inefficient tank of hot water. It heats the water only when you need it. When you turn on a hot water faucet, the heater senses the water pressure difference and immediately switches on the high-intensity heater.

High output gas burners or electric heater elements are used. As the cold water passes through the water heater, it is heated instantly. The gas units have the greatest hot water heating capacity.

These heaters are small and can be mounted on a wall in your utility room or basement. Some gas models have power vents to exhaust the flue gases outdoors through a small horizontal pipe. This is ideal if you want to convert from a costly electric water heater to a gas or propane instantaneous model. You will not have to build a chimney.

Although the initial cost of an instantaneous water heater is slightly higher than a conventional high-efficiency tank-type model, one should last a long time. They are designed with replaceable parts, so they can be repaired if needed. There is no tank to get rusty and leaky.

A lower cost option is to install a tiny instantaneous electric water heater under the sink just to serve that bathroom. If your bathroom is like mine, it takes over a minute to get hot water after you turn on the faucet. The tiny instantaneous unit will provide hot water in seconds.

You can write to me for Utility Bills Update No. 187 listing manufacturers of energy-efficient whole-house gas, propane and electric instantaneous water heaters and the tiny bathroom models, their hot water output rates and other specifications. Please include $1.50 and a self-addressed business-sized envelope. Send your requests to James Dulley, c/o Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.