Drain your water heater, increase efficiency

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:

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ckmapawatt's picture
After doing it myself, I think you may be right, but I wonder if there are other areas of the country that might have dirty water and a lot of sediment?
The posting about electric tanks is true, the sediment will rarely reach the bottom element. The need to flush out the sediment of a gas or oil fired unit will depend on the location. If it is municipal supplied water the need should be very low as far as frequency. However if you have your own well the amount of sediment may increase dramatically. Remember as water is heated it expands and stratifies - this means that suspended particles which are heavier will tend to fall or settle to the bottom of the tank. Although some tanks force the cold incoming water to the bottom with a swirling action, the sediment will only be carried out the top of the tank by a large continuous flow of water. This sediment many times will have a fair amount of minerals, sand, and possibly other dissolved solids. If you can hear popping and crackling from the hot-water tank during the burner cycle, this is usually the minerals and sediment causing little eruptions. This does decrease efficiency and shortens the life of the tank - also can be very loud and annoying. Flushing the tank periodically is good prevention. If you already have this problem - draining the tank, shutting the valve and letting several gallons of vinegar sit in the bottom for a few hours many times will dissolve the encrusted sediment. This has been my experience servicing over 700 systems. A clean machine is more efficient. Hope it helps.
ckmapawatt's picture
Jerry, that is one of the better comments I've ever received on a blog post! Email if you ever want to put up a guest post on increasing efficiency of hot water heaters!


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