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How Does a Furnace Gas Valve Work?

By February 15, 2019 Uncategorized No Comments

How Does My Furnace’s Gas Valve Work?

The gas valve on your furnace is one of the most important parts! Without it, your house would be quite cold!

gas furnace image

The gas valve on your furnace is one of the most important parts.

It is ultimately responsible for delivering an adjusting the flow of gas pressure to your furnace to keep it lit when running.

A gas valve replacement is a common furnace repair in older furnaces.

Let’s take a look at the different kinds and how they work to keep your home warm in the winter!

Types of Gas Valves

Combination gas valve: This type of gas valve was introduced around the 1960s.

A combination gas valve contains a handle, a thermocouple, a regulator, and a solenoid valve.

In essence, it contains everything needed for the operation of a gas fired furnace. 

Gas chain: These types of gas valves are quite common and require the operator to manually turn a valve to open or close the flow of gas to the furnace.

Once opened by the user, the solenoid valve will only open to allow gas to flow when the furnace actually calls for heat.

Otherwise, you’d have a non-stop flow of gas into your home!

A safety switch will only remain open if the thermocouple is heated to a minimum temperature, verifying the furnace is actually in heating mode.

How The Gas Valve Works

The furnace’s gas valve is operated by electromagnets.

There are two different valve’s that work in time with each other to provide the right amount of gas to your furnace.

The safety valve is what actually supplies the gas to the pilot light that will ignite the furnace burners during operation.

The other valve, the main valve, is what permits gas to be delivered to the burners themselves.

Your furnace has it’s own built in safety system via the thermocouple.

This little rod basically lets the gas valve know whether or not combustion (fire) is actually happening or not and whether the gas valve should remain open or closed.

If the thermocouple does not maintain a certain temperature, it knows that no combustion (fire) is happening and the gas valve closes to prevent gas from just leaking into your home for no reason.