Bringing Hot Water Closer to Tap

QUESTION: We have a bathroom that’s quite a distance from our water heater. We need to let the water run for a minute or so before we get hot water at the tap. I know this is very wasteful, so I’m looking for a faster way to get hot water at the tap. What do you suggest?

ANSWER: You’re not alone. This is a common problem in many homes and becomes especially apparent during a water shortage. It’s difficult to save water when it takes a minute or more for hot water to get to the tap in the first place. Also, it’s doubly wasteful because of the energy lost from the hot water stored in the long run of pipe to the tap.

You have several options. First, consider moving the water heater closer to the taps. The move would require some replumbing and relocation of gas or electric lines, and may be inhibited by lack of space for the tank or the configuration for gas flues. Still, it may be still the least expensive option.

Next consider installing a small point-of-use water heater under the distant tap. This will allow you to draw hot water instantaneously.

There are two types of point-of-use heaters on the market. One heats water instantly when you turn on the tap (also called a demand water heater). The other heats a small quantity of water, usually two to four gallons, and stores it in a mini-tank located by the tap.

Off the shelf, the demand-type heater is more expensive compared to the mini-tank’s cost. Both will require some plumbing. The demand units may also require wiring and installation of gas lines.

The advantages of the demand heater are a limitless supply of water, a choice of natural gas or electric and energy savings on water storage. The major drawback is a relatively low flow rate, usually less than one gallon per minute for the smaller models, about half of what you’d need to supply a shower.

The advantages of the mini-tank are no restrictions on flow rate and a ready plug-in at the electrical outlet. The disadvantages are a limited supply of hot water (four gallons is fine for hand washing and shaving, but makes a very short shower), and the power source is limited to electricity. Also there is some heat loss from the stored hot water, though tank insulation reduces this somewhat.

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Prepared by the Energy Extension Service, a division of the Washington State Energy Office.