Replacing Water Heater Gas Control Valve

Replacing Water Heater Gas Control Valve

The gas control valve on a gas water heater is an external control center that is located near the base of the water heater. It contains the thermostat and the pilot light controls. 

There are a variety of issues that can arise with a water heater, and the gas control valve can contribute to some of them, such as the following: faulty thermostat or gas valve, inability to light the pilot, and a tripped heat limiter. If these issues are occurring, repair and/or replacement of your gas control valve may be necessary. Read further to determine what components would need to be fixed and how to go about making the repair. 


The Function of a Gas Control Valve

When gas passes through gas pipes by way of the gas inlet, it then enters the unit through a connection to the gas control valve which is designed to dictate the flow of gas to the water heater. This valve helps light the pilot which in turn heats the thermocouple. When the thermocouple is heated, the gas control value signals the burner to heat the water in the tank. The heat limiter also functions by way of the gas control valve and is designed to sense when the heat of the water has exceeded safe levels and triggers the gas control valve to shut down.


In order to figure out what is causing the water heater to malfunction, you may need to troubleshoot the gas control valve and its associated components. Before determining the gas control valve in entirety is the cause for concern, check the other components to rule out their possible faultiness. It is actually a rare occurrence for a gas control valve to fail, so checking on the other parts that more commonly stop working such as the thermocouple Is your best course of action. Unlike the thermocouple which is inexpensive to replace, the thermostat and the heat limiter are more costly and may benefit from replacing the entire gas control valve for a slightly higher price in order to get a whole brand new system.

Gas Control Valve Replacement

WARNING: Always turn off gas before attempting water heater repairs as natural gas can be extremely dangerous to work with.

To execute a gas control valve replacement, first turn off the gas and then disconnect the lines connected to the gas control value with an open-faced or adjustable wrench. Hold the water heater steady when disconnecting connectors to avoid damages.

Go to a hardware or gas supply store and present them with the old gas control valve so they can help you get a new, matching replacement. Install the new gas control value using the reverse order of disconnection. If gas is not present, relight the pilot light and test the water heater for proper function.

Newer gas water heater models have sensor wires attached to the gas control value as a safety measure to turn off the gas in the event of a flash fire. Make sure to reinstall these wires after replacing the gas control valve. Hire a trained water heater technician to assist you in these repairs and/or replacements if necessary.

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