Tankless Water Heaters and Conservation

Overview

Being green and efficient with your home water use can make a big difference in your water bill and in your impact on the environment. Low-flow showerheads, faucets, tankless hot water heaters, dual-flush toilets, dishwashers and high-efficiency washing machines are all good options depending on your home's situation.

Conserving Water and Energy in Your Home

Green plumbers and water use specialists can help you install showerheads, faucets and appliances that use less water and conserve resources without noticeable differences. Outdoor systems like rain barrels can allow you to collect rainwater for both inside and outside your home. Low-flow showerheads and faucets are easy and cheap ways to reduce water usage. Depending on your hot water usage, you may be able to get a smaller hot water heater, thereby saving energy that would have been used to heat unused water.

Besides choosing a smaller hot water heater, you may want to choose a tankless hot water heater that will heat water as you need it. The tankless water heater fires up when you need hot water — when you turn on the hot water tap — rather than turning on and off all day and night like a standard storage water heater. The least efficient tankless water heater is still much more efficient than some of the most efficient rated storage tank water heaters, but to get the most savings, you should look for a tankless with an Energy Factor or 0.82 or better.

If you plan to purchase a traditional hot water heater, make sure to look for the ENERGY STAR label, and from there, look for a water heater with the highest Energy Factor you can afford. It will save you much more money in the long run than a less efficient system. Also, if you plan to purchase a standard water heater, a water use specialist can help you determine the size of system you and your family will need.

Tankless hot water heaters, dual-flush toilets and high-efficiency washing machines and dishwashers are some of the green choices that may be recommended by water-use specialists. Another option is a dynamic temperature setting for a hot water heater, or boiler, that varies the temperature of your hot water heater. When it's cold out, the water is heated to a higher temperature for comfort and when it's hot outside, your hot water heater setting is automatically decreased.

What Kind of Hot Water Heater Do You Have?

Hot water heaters are commonly either fueled by natural gas or electricity, and they can be either a regular tank storage system or can be tankless. Less common types of hot water heaters include tank storage water heaters that are heated by oil, indirect water heaters that are connected to your boiler, and solar hot water heaters.

Standard Gas: If your hot water heater is a big cylinder that looks like it holds a lot of water, you've got a storage tank type. If you have natural gas for your furnace, you should look for a gas line running to your hot water heater and a pilot light on it. If you see those, it's a dead give-away that you've got a standard gas tank storage hot water heater.

Standard Electric: If you've got a big cylinder full of water and there's no gas line connected to it or pilot light on it, it's probably an electric tank storage hot water heater.

Tankless Gas: If you can't find a water storage tank in your home and you've got a natural gas furnace or other gas appliances, you might have a tankless hot water heater or two. They are usually small boxes (2 x 2 feet or smaller) that look like they are attached to both the water pipes and a gas line.

Tankless Electric: If you can't find a water storage tank, you don't have natural gas for your home and yet hot water still comes out of the faucets and shower, then you've either got something unusual (like solar or indirect hot water), or you've got tankless electric water heaters. These units usually look like small boxes (2 x 1 feet), and they've got water pipes and electric wiring coming out of them.

Last Updated: April 2010

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