|
| Figure
3 Typical gas water heater cut-away showing anode rod
and cold water dip tube. |
 |
|
| 7. |
Pour 1/2 gallon of household bleach, or better
yet several pints of hydrogen peroxide into the water heater.
Use the T&P valve, anode rod or hot water outlet pipe opening
to pour the chlorine in. Re-pipe the water heater and close
the T&P valve. |
| 8. |
Open the cold-water inlet at the
heater and fill the tank with water. Observe the water level
through the closest hot water faucet. Close inlet valve when
the tank is full. |
| 9. |
Leave the bleach mixture in the heater
for one hour. |
| 10. |
After one hour, open the cold valve again,
open all the hot water faucets and allow the bleach mixture
to clean the hot water supply pipes. Drain the remaining chlorine
or hydrogen peroxide solution from the tank through the heater
drain valve. |
|
| 11. |
Close the heater drain valve, and completely
fill the tank with fresh water. Leave the water in the tank for 15
minutes. |
| 12. |
After 15 minutes, purge the hot water supply
lines and drain the water from the tank though the heater drain valve,
flushing out any sediment if present. Close the drain valve. |
| 13. |
Make sure you purge all air from hot water
lines from the open hot water faucets. Close the hot water faucet
after all the air is out of the system. |
| 14. |
Check for water leaks at all fittings used; repair as necessary. |
| 15. |
Turn on the manual electrical switch, or turn the
gas control knob back to “On” and verify that the heater
burners have lit and turned back on. |
| 16. |
Check for normal water heater operation. |
| If the Odor Returns to the Hot
Water |
| After this procedure is completed,
the odor will be eliminated. If it returns within a few weeks, then
the chlorination procedure can be repeated. However, in many cases
the cold water will still have problems with recurring odors due to
continued presence of sulfate bacteria and low chlorine residuals
in the water. |
| Some solutions (for those on
municipal water systems with odors in the water heater) are: |
| • |
Remove the anode rod and replace
with an aluminum/zinc anode rod if you haven’t already. |
| • |
Replace the water heater with a plastic
lined water heater, an instantaneous water heater, or a commercial
stainless steel water heater (none of which have anode rods). |
| 4. More
about water heater anodes and water heater corrosion: |
| Thanks to www.waterheaterrescue.com
for the following information. For useful information on service and
maintenance to water heaters visit their site! |
| All glass-lined water heaters have
sacrificial anode rods. This is a rod made of magnesium or aluminum,
that's formed around a steel core wire, and is screwed into the top
of the tank. Physically connected to the steel of the tank, it creates
an electrochemical reaction, similar to that of a battery, whereby
the anode corrodes and the steel remains intact. When there's no sacrificial
metal left on the anode, the tank rusts out. |
| All metals fall somewhere on the
galvanic scale, and the "nobler" ones will remain intact
while the lesser ones will corrode. When steel and copper are touching,
the steel will corrode while the copper remains intact. That's why
dielectric unions are necessary on items like copper flex connectors. |
| Magnesium and aluminum are less noble
than steel, which is why they're used for anode rod. The anode rod
can be unscrewed and replaced, even though it’s difficult sometimes
to get the old anode rods out sometimes. An anode's life depends on
the quality of water, the amount of use the tank gets and the quality
of the tank. If the water is aggressive or corrosive, the anode rods
should be inspected yearly and replaced as needed. |
| Removing the Anode Rod |
| 1. |
Close the cold-water gate valve. |
| 2. |
Turn the control to pilot if gas, or turn
off the electrical power switch if electric water heater. |
| 3. |
Remove the vent pipe to allow working room, a gas water heater. |
| 4. |
Open a hot-water fauce to relieve pressure.
If the hot water doesn’t stop running after you open a faucet
in the house, then the gate valve cold-water shut off is not shutting
off completely. At this point, turn off the main water line to the
house and replace the valve if needed. |
| 5. |
Let a gallon or so of water out the drain valve. |
| 6. |
Locate the anode rod. On some tanks, the hex head
of the anode is exposed and in sight, such as in this picture. On
others, it's hidden sometimes under a sheetmetal top that's foamed
into place. |
| 7. |
Remove the anode rod per the following tips: |
Top of typical gas heater,
vent pipe rmoved |
 |
|
| Anode rod is located on the top of the water heater
tank near the back and usually has a hex head. |
 |
|
| In some applications, the anode rod is hidden beneath
sheet metal, and one must drill through the sheet metal (not too far)
and then use a screwdriver to feel around and find the hex head. The
anode will most likely be on the backside of the tank, 1 1/2 inches
out from the flue in a semicircle between the hot and cold ports. |
| Once it's found, drill another hole and use it as a
start for cutting a hole with tin snips to give access to the anode.
Be careful of the sharp sheet metal edges. |
| On some water heater tanks, there is no hex-head
anode, just a combination nipple/anode/hot water outlet, shown
on the right. You can determine this by disconnecting the hot-water
side flex connector, and running a long screwdriver or similar
implement down the nipple. If it stops after a couple of inches,
it has run into the combo rod. Original anodes are not installed
with pipe thread seal tape and they can be very hard to remove. |
| Take a 1 1/16-inch
socket wrench and a cheater bar to put on the end of it to give
maximum leverage, and loosen the anode. |
| The new anode rods are 44 inches long. Pulling
out the old one can be accomplished by bending it if there is
no headroom. A new one can in some cases be bent when installing
and then straightened there is lack of headroom above the water
heater, or you can get anode-rods that’s are. |
| In some cases you may have to use a segmented
anode, which has been milled down to the core wire, which is
soft. That allows the segments to be bent, inserted in the tank,
and straightened out. |
| In some cases, if there is a vent, you can run
the anode rod up the vent pipe and then back down. |
| If more than six inches of core wire is exposed,
or the anode is splitting, replace it. Put the new one in with
pipe thread seal tape to make next removal easier. |
|
 |
| If you cannot get the old anode rod out, you can install
a combination anode/nipple rod on the hot side. Disconnect the hot-side
plumbing, remove the old nipple with a pipe wrench, and put in the
new rod (with pipe thread seal tape!). |
 |
Galvanized steel nipples (left) will
eventually rust and corrode, causing the nipple to plug up with rust.
They may collapse if they need to be removed. It is better to use
a plastic-lined dielectric steel nipple (right), which can't react
with water or other metals. |
 |
|
