Since water heaters guzzle energy--and moolah--you can save loads by simply dialing down the knob. Water tanks store a supply of water, using energy to keep water hot and ready to go for your AM shower. Dropping it 20 degrees, from 140 to 120, and you can returns of 5-10 percent on your heating bill. Much better than throwing money down the drain!
Or, if you're in the market for a new one, tankless water heaters are a great, green option since water isn't stored.
photo: via stockxchang/desertsnow