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Water heater problems

by ALAN MALONEY

The Problem

The two questions I have been asked the most over the years are how to get rid of mildew on the outside of the house and what is causing the water heater to rumble. This is about the latter. The water in some areas contain calcium and magnesium salts. When the water is heated or frozen, the dissolved salts precipitate out. If you live in a hard water area, I'm sure you have noticed the "what the heck is this" stuff in the bottom of a glass that had contained ice and left undisturbed several hours. The stuff is in the salts.
When boiling water, I'm sure you have also noticed the residue left in the pot. In you water heater the same thing is happening on a much larger scale. Over time, as little as a year in some areas, you will notice the gas water heater rumbling when it is heating. No it isn't about to blow up, but it is now much less efficient.
In a clean water heater, as the water is heated, it rises to the top of the tank and the cooler water falls. This convection removes the heat from the electric heating element, or the bottom of the tank in a gas water heater, fast enough to avoid equipment damage and keeps the water from boiling. When the water reaches the desired temperature necessary to satisfy the thermostat, the heat source turns off.
As the mineral deposits build up in the heat, they cause several problems. In all cases, they take up space. Your water heater holds less water. After cutting them open, I have seen water heaters with deposits 2 feet deep. That was 40% of the tank capacity displaced by sediment.




Electric Heaters

The deposits also act as an insulator. In electric water heaters, the deposits form on the element then flake off and fall to the bottom of the tank. Once the deposits pile up above the lower heating element, often, the element will overheat and burn out. There are now elements that can take the extra heat, which is only treating the symptoms, not the problem.

Gas Heaters

Gas water heaters are heated by a gas flame under the tank. The deposits form at the bottom inside the tank. Since the mineral deposits act as an insulator between the heat source and the water, the bottom of the tank itself overheats causing the water in the mineral deposit slurry to momentarily boil. The bubble formed expands quickly lifting the mineral deposits causing a rumbling sound. (You can duplicate this process by placing two inches of sand in a medium saucepan; add enough water to cover the sand by at least an inch and putting the pan on high heat.)
Mineral deposits in the water heater are expensive. The more mineral deposits in the bottom of the tank, the more energy it takes to heat the water and the hotter the bottom of the tank gets. Since this overheating will eventually burn through the tank bottom, this shortens the life of the heater.

Solving The Problem

There are three ways to deal with this problem. One is regularly cleaning out the water heater. Under even the best conditions, this is a lot of trouble, a mess and time-consuming. You can install a water softener on the main water line to your hose and replace the water heater. You can replace the water heater with a self-cleaning water heater made by State Industries.


Cleaning the Water Heater

In a gas water heater, the deposits form on the bottom of the tank and are for the most part stuck to the tank. Flushing out the heater will only remove a fraction of the deposits in there. Electric water heaters collect the mineral deposits on the heating elements (usually two), and they flake off and fall to the bottom of the tank. Some of them can be flushed out however often the particle size is too large to flush through the drain valve.
Below you will find the steps involved in flushing and cleaning the water heater. Read through all the steps and think about the effort involved before starting. Once you get the cleaner in the heater you are committed to finishing all the steps or you will have very sudsy hot water for some time to come.
Keep in mind that if there are a lot of deposits in the tank, you may need to go through all of the steps more than once. If you water heater is over 7 years old or is starting to rust or leak, this operation could cause the water heater to leak so much you will have to replace it.
1) Turn the water heater off.
2) Turn the cold water supply to the water heater off.
3) Hook a good quality reinforced garden hose to the drain valve.
4) Place the other end of the hose where HOT water will not cause damage. The hose should be placed so it is straight as possible. If not, all turns should be gradual.
5) Open the drain valve.
6) Disconnect the cold-water inlet pipe on the top of the water heater. (This will let air into the water heater so it will drain).
7) After the water heater is empty, close the drain.
8) Pour a gallon of acidic tub and tile cleaner (C.L.R. is the only brand I have found packaged in the more economical gallons) into the cold water inlet pipe ONE CUP AT A TIME. Pause a few seconds to let the tank breathe before pouring in the next cup. Failing to do this will result in the heater belching cleaner all over you and the surround area.
9) Several hours later, drain the cleaner out. The cleaner will have either dissolved all the mineral deposits or have been neutralized by the deposits. The check if the cleaner is still working, gather the open end of a small plastic bag tightly around the open cold-water inlet pipe on the heater. If the bag gradually inflates, the cleaner is still working. (If you are really compulsive, when the cleaner quits working, you could drain the residue out, put in another quart of cleaner and see if the bag will then inflate. This will tell you there are more deposits to dissolve.)
10) Reconnect the cold-water inlet pipe. (NOTE: If you have the flexible type of connectors, you must first smooth the top of the pipe nipple coming out of the water heater with a flat file. You also need to either replace the rubber washer in the connector or turn it over. When tightening the connector onto the nipple, it only needs to be snug. Failing to smooth the nipple, replace the washer or over tightening the fitting will result in a leaky connection.)
11) Open the cold water inlet valve and let the water heater flush for several minutes.
12) Close the drain valve, open the hot water faucet nearest to the water heater and let the water heater fill.
13) When water starts to come out of that faucet, reopen the drain and let the water heater continue to rinse.
14) Once the water seems clean, close the drain; open all the hot water faucets to remove all the air from the water heater and hot water pipes.
15) After all the air is out of the water heater, turn it back on.
For a day or two, you may get a slight amount of suds from the hot water faucets when you first turn the water on. By this time, however, the cleaner is so diluted, there is no harm. Now that you have gone through all this you may still have some rumbling from your gas water heater. This means you did not get all of the mineral deposits out of the tank. It's back to step one. I told you in the beginning that this is a lot of trouble.

Preventive Maintenance

To help keep your water heater clean, every two to three months flush it. That is, hook a good quality reinforced garden hose to the drain valve. Place the end of the hose where HOT water will not cause damage. The hose should be placed so it is as straight as possible. If not, all turns should be gradual. Open the drain valve and let water flush through the heater. The incoming water will agitate the sediment and some of it will actually flush on out.
"Some of it", because, the standard water heater drain valve will only let very small particles pass through. By replacing the existing drain valve with a 3/4 inch ball valve equipped with a 3/4 inch male pipe thread to make garden hose thread adapter, when you flush the water heater periodically, you will remove most of the free floating sediment. In a gas water heater, it is important to remember that some of this sediment is actually stuck to the bottom of the water heater and will not "flush" out.
A ball valve goes from full closed to full open with only a quarter turn. It also has a large bore, which will let larger particles pass through. By "flipping" the valve open and shut quickly, you can agitate the sediment in the water heater and more of it will flush out.
To be safe, I place a metal garden hose cap with washer on the end of the hose adapter. That way, if someone accidentally kicks the valve open, no harm will be done.