03161 Lower Your Hot Water Bill with a Simple On-Off Switch

I believe in getting into hot water. It helps keep you clean. — G.K. Chesterton

When it comes to cutting your hot water bill, many people reach for the “on-demand” water heaters. Their problem is high capital costs for purchase and installation.

Fortunately, there is an easy and “value priced” hot water option for people with electric water heaters: install an on/off switch.

Tank water heaters waste energy when they keep a tank of water hot 24/7/365.

Installing a simple on-off switch on an electric water heater is a value priced way to finesse this problem without spending as much as on-demand heaters cost.

We went with the value price option. We had to rewire our house anyway, so we bought an off-the-shelf mid-priced electric water heater from a big box store. We had the electrician install an on-off switch for the hot water heater. You can get the same result by flipping the breaker switch, but most breaker boxes are outside. We decided we would be more likely to actually do this if we located the switch inside and we did not have to go outside to turn it on or off.

We intend to add a solar water heater as the implementation of the permaculture design for our home progresses. When this happens, our present tank will become back-up heating and storage for the solar system.

Electric water heaters are much better insulated than natural gas or propane water heaters. They don’t have a chimney in the middle, so the tank stays hot longer.

We added insulation to the tank by wrapping fiberglass insulation around it and securing it with duct tape.

The new switch, installed by itself, without any other electric work, would cost about $200 according to a bid solicited by a public television program that did a documentary about our house. We installed our switch as part of a whole-house re-wiring, and that particular job was not priced separately from the others.

When the hot water tank has cooled to the ambient temperature, it takes only about five minutes after we turn on the switch to get a stream of hot water.

We installed a low flow showerhead to reduce our hot water usage. We like its spray better than our previous standard showerhead. It cost about $11 at a big box store and we installed it ourselves.

We love our on-off water heater switch and the money it saves us. This was one of the best innovations we implemented in our ongoing quest for the Extreme Green.

Oklahoma solar hot water installer David Nordahl described a second alternative in a discussion in the Oklahoma Sustainability Network listserv.

At his house, he has two, small electric water heaters — one in the bathroom (8 gallons) and one in the kitchen (4) gallons. Since they are small, they work on 120 volts. He has a solar hot water system, and the tanks are back-up and storage for the solar hot water. This has an added advantage of providing nearly instant hot water without an expensive re-circulating system. The capital costs are low, since it doesn’t use 220V wiring.

All of us need to head towards solar hot water systems. Both of these systems will work well as back-ups for solar hot water systems.