Set the thermostat to 120 degrees.
If your water heater lacks a thermostat, check the temperature by running an instant-read cooking thermometer under hot water at the kitchen sink. Electric water heaters have two thermostats – don’t forget to lower them both.
Insulate the pipes.
Use pipe insulation or self-adhesive pipe-wrapping insulation tape to insulate the first 3 feet of pipes entering and leaving the water heater. Just don’t wrap the actual water heater – that could cause problems.
Turn it off when you leave town.
No need to heat water when you aren’t at home for more than a few days. Some natural gas heaters even have “vacation” settings. Just don’t forget to turn it back on when you get home – it will take at least an hour to re-heat.
Conduct regular maintenance.
Your manual will tell you how to keep your water heater happy.
Buy the right size.
50 gallons is usually sufficient for four people. If you are shopping for a new water heater, look for a high energy factor number – the higher the number, the more efficient it is!