Homeowners: if you have a storage tank water heater (you most likely do), then you need to drain and flush it periodically (every year is the average). Why? Sediment and other crap builds up in the tank over time, causing inefficiency and possibly even damage, if left unchecked.
Here’s a good how-to on flushing it: http://www.wikihow.com/Flush-a-Water-Heater
I flushed mine last night, and learned some lessons the hard way. Here’s what I learned.
If you have an electric water heater, double-check and then check again that you’ve turned off the breaker switch for the water heater, before you start draining it. If the electricity is on, you will burn out one or both heating elements. I managed to turn off my dryer instead of the water heater, and burned out my top heating element. For some reason, the folks who labeled my breaker box didn’t label correctly, according to the numbers; the labels were off by one slot. The breaker box had a blank slot on the top, but the label grid started at the top, and had the blank spot at the bottom. It was easy enough to figure out if I had double-checked.
Heating element replacement
If you do end up burning out a heating element, don’t despair. You don’t need to spend a bunch of money on a professional, and parts are cheap. A new heating element will run you $10 or so, and replacing it is as simple as draining the tank again, opening a panel, and replacing a screw-in part. Instructions should be on the back of the heating element package. There are also some how-to pages and videos on the internet.
Watch out, though: you may have only burned out one heating element (electric heaters have two). To figure out which one, you need a continuity tester or a multimeter. Turn off the electricity again, of course — and verify that you have done so, if you don’t want to die — and then test the heating elements. Disconnect them (leave them screwed in, though), and then test resistance across their leads. If you get something like 10-16 ohms (or a closed circuit, if you’re just using a continuity tester), the heating element is good. A bad heating element will read as a very high resistance (multiple kohms) or an open circuit. Once you’ve tested the heating elements, you’ll know how many you need to buy and which one you need to replace. I burned out the top one.
When you go to get the new heating element(s), make sure you also get the giant socket-like wrench that is needed to remove and replace them; it should cost $6 or $7. The one I got was basically a short pipe, with a hexagonal end. The other end had holes cut through it perpendicular to the “pipe’s” length; I put a long screwdriver through these holes for leverage.
Replacing the heating element only took me about an hour — most of that time was spent waiting for the tank to drain, and waiting for it to fill up before I turned the electricity back on.
