Water heating is commonly listed as the second highest energy load in the home.  Of course this depends on how big your family is, and what energy source you use to heat your water (electricity or natural gas).  We use natural gas, and based on how low my summer natural gas bills are (we also use natural gas for winter heating) I know that heating our water isn't costing us that much (maybe $7/month).  With that said, there are a few things you can do to decrease your water heating bills, and draining your water heater is one of them. Yesterday I drained my water heater for the first time in over 3 years.  The purpose of doing this is to clear out any sediment that may have settled on the bottom of the tank.  The amount of sediment that may collect in your hot water heater storage tank depends on the quality of the incoming water, but you really don't know how clean or dirty it will be until you do it once or twice. I followed the steps from DIY Network on How to Drain a Water Heater.  Make sure to read that post and also read your water heater's instruction manual.  The important things to remember are cutting off your power source (electrical breaker or natural gas) and shutting off the cold water intake.  You also want to open up a hot water faucet inside to prevent any water or air from getting stuck in the lines.  But I don't want to oversimplify the process, so read the above link!

My results were pretty underwhelming.  There was some sediment, but I'm not sure it if justified wasting a whole bunch of hot water in my driveway. The process did help me learn that my water quality is pretty good, so I probably don't need to do this every year. Energy Savers also recommends the following, which may make more sense for me going forward:

Drain a quart of water from your water tank every 3 months to remove sediment that impedes heat transfer and lowers the efficiency of your heater. The type of water tank you have determines the steps to take, so follow the manufacturer's advice.

I'm curious to hear if some of you have done this and what your results were.  One thing I did notice was that the hot water supply pipe from the water heater to my home has about 2 feet of exposed copper piping!  I've lived in the home over 3 years and never really paid attention to this.  Heat is escaping from this pipe into my garage area, so I'm going to head to the hardware store and pick up some pipe insulation asap! Aside from draining your water heater, here are some other things you should read if you are curious about saving energy related to heating water:

• Solar Thermal water heating
• Water heater temperature
• Electric heat pump water heater
• Tankless water heater