Many furnace problems stem from issues with the gas valve. Yet this component remains a relative mystery to many homeowners. By increasing your knowledge of the role played by the gas valve, you can greatly help to improve your skill in diagnosing common furnace ailments. This article will take you through some of the basic information regarding gas valves.
Gas Valve Anatomy
Though the gas valve is generally referred to as a single component, it incorporates a lot of different parts. Among these are actuators, coils, thermocouples, and the pilot light assembly. The actuators are responsible for allowing or restricting the flow of gas through the valve. The coils are responsible for actually opening up the actuators when triggered by electrical impulses from the thermocouples.
When the pilot light is on, its flame heats up one of the thermocouples. This in turn causes the thermocouple to release a steady electrical impulse that keeps the first actuator open, thus allowing gas to continue flowing to the pilot. When your furnace receives a call for heat, the second actuator is temporarily opened. Should combustion occur, it will heat up yet more thermocouples, whose job is to control the position of the second actuator--that is, the one allowing gas to flow through the valve into the combustion chamber.
As you probably know, gas furnaces represent a potential hazard should they begin emitting raw gas into the air. The gas valve is designed to keep this from happening. If combustion ceases, one or more of the thermocouples will fail to maintain the appropriate temperature. As a result, they will no longer produce an electrical signal, and either one or both of the actuators will close, thus restricting the flow of gas.
If you believe that your gas valve may be in need of repair or replacement, contact the professionals at Indoor Comfort Team.