There are times when you are faced with the problem of a dysfunctional water heater and most often than not this is caused by the water heater gas valve. There are two main valves in a gas water heater and they are the drain valve and the TPR valve. The TPR (Temperature Pressure Relief) valve is also known as the just relief valve, or the pop-off valve and it is basically a safety device. The primary use of this valve is to release excess pressure from the tank and thus keeps it safe. The drain valve is used for draining out sediment, which gets formed after months of regular use.
Most of the times, it is the gas control valve or the relief valve that causes a problem. It can be repaired, rectified, or replaced.
How to Install a Water Heater Gas Valve
If you have to replace the gas control valve or the water heater gas valve then you need to first buy a new one from the market. Always make it a point to buy a valve of high quality rather and never compromise on the price.
Step#1: The first step towards replacing the water heater gas valve is to shut off the water supply and the gas supply to the water heater tank. Normally, the shut-off button or lever for water supply will be at the top of the heater near the incoming water pipe. The button or lever for gas shut-off will be located on the or near the gas pipe.
One of the important things to remember here is that if there is water in the heater tank then you need to drain it completely by attaching a garden hose to the drain valve. You can drain the hot water in the sink, in your garden or in the bathroom.
Step#2: Now open the drain valve and gradually loosen one of the flex connections. You will find this connection at the top of the water heater tank and this will help in breaking the vacuum. The total time for the exercise will depend on the capacity of your water heater and should ideally be complete within 15-20 minutes.
Step#3: Once you have successfully drained the tank you can now prepare for the installation. The next step would be to disconnect the water heater gas valve. In order to do that, you will have to first disconnect the gas flex hose using a simple adjustable wrench.
Step#4: Now you need to disconnect the three tubes, which are connected from the bottom of the gas valve. These three tubes from left to right include the pilot tube, the burner tube and the thermo-couple. You will need to loosen the nut/bolt securing each of the tubes as they enter the gas valve. Once you have loosened the nut, pull down each of the tubes to release them from the gas valve. Ensure that you don’t use too much force and don’t misplace the nuts/bolts as they will be required to secure each of the three tubes after the water heater gas valve has been replaced.
Step#5: The next step is to remove the water heater gas valve from the tank. You can use a pipe wrench or a pair of large channel locks to unscrew the gas control valve from the water heater tank. This is probably the original valve that was installed or fitted at the factory.
Step#6: Once you release the valve, you will notice a threaded nipple at the back of the valve. This is called the shank. You will need to determine the actual length of the shank. You need to remember that there are two different lengths available for gas water heater shanks and they are: 1 3/8″ and 2 3/8″. You need to have a replacement shank of the same length as the one on the existing water heater gas valve. This will ensure that the pilot tube, burner tube and thermo-couple match up.
Step#7: Now add Teflon tape or pipe dope to the thread of the shank so that it can prevent leaks.
Step#8: Now go in reverse and connect the water heater gas valve to the tank. Follow the entire process backwards to attach all the points that were disconnected from the heater.
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