Every water heater contains a long metal rod known as an Anode Rod, which is an alloy of several metals. The role of this rod is to protect the tank against corrosion by first corroding itself.
As soon as the anode rod is fully corroded, the tank will begin to corrode. In order to keep your water heater protected against corrosion, you must replace this essential component regularly.
Keep in mind that the following instructions are broad and offered solely for the convenience of our customers. No obligation is assumed by ClovisPlumbingServices.com with respect to your use of these guidelines.
Note that different or further instructions may be required by the many varied water heater brands. We highly suggest you consult with your water heater manufacturer before commencing this task.
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Anode Rod Replacement: Step 1
Detect the anode rod. It is commonly located on top of the heater unit, but some have it on the side. It also commonly resembles a hexagonal plug screwed into the heater.
In some heater units, the anode rod is connected to the hot water outlet port and looks like a pipe nipple. For these kinds of anode rods, please refer below to the section “Anodes at Hot Water Outlet”.
Shut off the heater unit’s power switch. Flip the circuit breaker switch for electric heaters. If this is not done and air reaches the heating element, it could burn out.
For gas units, set the gas regulator to the lowest possible or to “vacation”. Try not to turn it off completely so as not to light up the pilot light all over again.
Step 3 & 4
Shut the heater’s cold water supply off.
Attach a normal garden hose to the drain valve which is at the heater base, and direct the hose outside the house or to a drain. Ensure the hose stays lower the water level contained in the tank so as to drain out the water.
Note that the water will be hot during drainage through the hose, so be cautious when handling. Only little water will be drained until after step 5.
Note: For anode rods situated at the top of your heater, the tank only needs to drain about ½ a gallon or a quart of water. For anodes situated on the side, the tank should be drained until the water gets below the anode rod port.
Now shut the outlet valve and detach the hose.
Anode Rod Replacement: Step 5
Turn on the hot side of a faucet nearby, relieving pressure in the tank by letting air through it to break the vacuum and enables the heater to drain.
If there is still pressure in the tank as you try to loosen the anode, it could jump out at incredible speeds!
To detach the anode, use a 1-1/16” socket wrench or closed-end wrench and breaker bar or ratchet on the hexagonal head. Since these rods are installed and remain in the heater over many years, it may be quite difficult loosen.
You can try to either use a breaker bar for more leverage or tighten the rod a little bit to help loosen the threads. Moreover, the pipe connections could be damaged from moving the water heater unit around.
If your heater is not strapped you should have it held by someone while you try to get the anode loose.
Ensure NOT to bang against the anode, as this could damage the glass lining within the tank and enable corrosion. Also, DO NOT make use of any chemicals to loosen the threads, as your water can be contaminated by them.
After loosening the anode remove it from the heater unit. You may have to bend it in order to remove it, depending on the amount of clearance available above the heater.
In general, since the anode is meant to corrode inside the tank, there isn’t any much left of it by the time it has to be replaced.
If at the time of removal, you discover that the anode seems to be stuck and cannot pull through the inlet hole being that it’s enlarged, then it means the anode material left can still function properly and as such does not need replacement at the time.
Here, you can just have the anode screwed back in to the heater unit for later.
Use PTFE thread sealing tape to wrap around the threads of the replacement anode rod in a direction from left to right (if you are holding the rod and seeing the threads) or right to left (if the rod is positioned upright and you are seeing the nut’s face).
You need only about 5 or 6 wraps round the threads. Otherwise, you could use a superior thread sealing compound.
Anode Rod Replacement: Step 9 & 10
Place the new anode rod in. Anode rods are mostly straight and bending can be difficult, so you can consider a flexible anode if you have limited space.
Using a 1-1/16” socket wrench or closed-end wrench and ratchet, tighten the inserted anode. At this point you should also have the heater unit held by someone to avoid damages to the pipe connection as a result of movement.
Anode Rod Replacement: Step 11 & 12
Refill the heater tank by opening the cold water supply, while the aforementioned faucet is opened to the hot side.
As soon as water flows out from the faucet, the tank is full. Allow the water to flow continuously until all the air within the tank is discharged. This can be determined when the faucet doesn’t spit out any more air and the water runs freely.
Anode Rod Replacement: Step 13 & 14
Inspect the heater connections for any leakages.
For electric heaters, turn on the power switch. For gas units, set the regulator to its previous temperature.
Anodes at Hot Water Outlet
In some water heaters, this may be installed on the outlet side, and requires replacement alongside typical anode rods. Here, the replacement process is a bit different since it is connected to the outlet plumbing.
In most cases, you’ll find a flexible connection to the nipple of the anode from the hard plumbing. Here you can easily loosen the nut of the flex line connected to the nipple. You can then use a pipe wrench to remove it and replace as described above.
Some rare cases have the hard plumbing directly connected to the nipple of the anode, without any flex line. This may be more challenging, given that you would need to cut the rigid pipe to access the anode. And then you need to replace the pipe as well
Here, we highly suggest you hire or consult a skilled plumber prior to removing these.
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