Proper installation and maintenance of your demand water heater can optimize its energy efficiency. Proper installation depends on many factors. These factors include fuel type, climate, local building code requirements, and safety issues, especially concerning the combustion of gas-fired water heaters. Therefore, it's best to have a qualified plumbing and heating contractor install your demand water heater. Do the following when selecting a contractor:

• Request cost estimates in writing
• Ask for references
• Check the company with your local Better Business Bureau
• See if the company will obtain a local permit if necessary and understands local building codes.

If you're determined to install your water heater yourself, first consult the manufacturer. Manufacturers usually have the necessary installation and instruction manuals. Also, contact your city or town for information about obtaining a permit, if necessary, and about local water heater