Domestic Hot Water Heaters
If you are like me, and most of the home owners in the US, you still have a hot water heater and dont think about them until they spring a leak or just quit working. There isn't really a lot to a hot water heater. Most guys put them in and say ok till I have to replace it again.
In the US there are a few things that differ from one place to another, or from the city to the rual areas. In the city, for the most part the water is treated. The water is filtered and countless other things. This is good. It will help keep the inside of your heater clean. But, there are still things that go in and settle at the bottom of your heater. This is why once a year you might want to consider putting a garden hose on your heater and draining it. This is done after you let it cool and you put your heater to pilot, if it is that type. If electric cut the power to the unit. This way you aren't heating all of the water you are about to dump, and don't want to do damage if the water gets too low.
When you first start this you have all the water coming in. After a short time: 3-4 minutes, close the water coming into the heater. You will notice the water flow will almost stop. This means it is going to need the little valve opened on the side. Lift the little handle on the top of the valve and you should hear air being pulled in. If you get water this means the valves (supply) is still open and needs closed tighter or it will not close. In this case put things back to the way they were.
But if you get the air and then look at the water flow, it should have started back not with a big amount, just a little. You will have to wait for a while till this stops again, but first you will see some dirt and rust or sediment. These are the things that cause the inside to oxidize and rupture(leak). At this point, open the supply water a little bit and flush the heater until it flows clean . Start to refill. Make sure the valve on the side of the heater is closed . This should be done once a year. Check for leaks and then put back in service