Fighting Mineral Build-up: Public Enemy #1 for Your Water Heater

Water heaters are the wallflowers of home appliances. They are easy to ignore since they sit in the corner of your basement and are rarely noticed. At least, they are rarely noticed until something goes wrong. Paying a little more attention to your water heater can prevent that sinking feeling of walking into your basement and discovering your feet are soaking wet.

Water heaters generally last anywhere from ten to fifteen years. The main factor in the longevity of your water heater depends somewhat on the quality of the heater you purchase, but mainly on the type of water that runs to your heater. Public Enemy #1 for all water heaters is a water supply chock full of minerals and impurities. If you receive your water from a municipal supply line, chances are your water is "conditioned" to remove many of the impurities that can cause deposits to build up in your tank. If your water comes from some other source, like a well, your water heater will likely be doing battle with its Public Enemy more often.

To get the most use out of your water heater it should be serviced regularly, just like a car. Some of this servicing you can do yourself by reading the maintenance section of the instruction manual. Two basic maintenance jobs need to be performed on your tank every few years: 1) checking the anode rod, and 2) flushing the tank.

The anode rod is a component that is built into the water heater so that the rod will corrode before your tank does, protecting you from an unwanted flood. The anode rod reacts with minerals in the water, and slowly rust away in order to prevent the metal of the tank from rusting. The rod is made of magnesium with a steel wire core. The magnesium will gradually disintegrate, exposing the steel core.

Water heaters generally have one anode rod screwed into the top of the tank. The 1 1/16-inch hexplug mounted on the top of the tank is used to secure the anode in place. Some heaters are built so that the anode rod is hidden under the sheet metal top of the water heater. This means you will not be able to see the plug, or unscrew it to replace it. If you are looking to buy a new heater, be sure to avoid this kind. If you already have a heater like this, there isn't a lot you can do to prevent your heater from rusting out. Your best bet will be to determine when the heater was purchased and replace it before its estimated life expectancy arrives.

Checking the Anode
Once you are ready to check the rod, cut the fuel supply and turn off the cold water source to the heater. Unscrew the top plug and pull out the tube. If mineral deposits encase the rod, (which can shield the rod and prevent it from reacting with the water), or if six inches or more of the steel core wire is exposed, it's time to replace the rod.

Flushing the Tank
Sediment collecting at the bottom of your tank slows the transfer of heat from the heat source to the water. Even a thin layer reduces heater efficiency, since the heater is working to warm up sediment and not the water. A thicker layer can cause your tank to overheat, accelerate corrosion and possibly burn out the heating element if your water heater is electric. If you hear a rumbling sound in the tank as water heats, that indicates the presence of sediment in your tank. If you discover sediment trapped in aerator screens on your spigots this is also a warning sign that your tank is holding sediment.

You can clear the sediment yourself by screwing a garden house onto the drain valve at the base of the tank, opening the valve and letting a few quarts of water drain out. You can let the whole tank drain by cutting off power, closing the cold-water inlet valve, and opening a hot-water tap in the house. You will probably get better results by letting cold water flow in and stir up the sediment as you drain off some of the hot water. Consult your owner's manual for the specifics relating to your water heater.

Plan to flush your tank every 2 to 3 years, (more often if you get your water from a well), and note the amount of sediment build up as a reference point for when you should next examine your tank.

While adding another item to your list of household "to-do's" isn't the most appealing thought, it is much better than stepping into a wading pool where your basement used to be.

Sources: Mike McClintock, The Washington Post