The furnace gas valve operates by electromagnets. The primary valve — also known as the safety valve — supplies gas to the pilot light. … Without adequate heating of the thermocouple or thermopile, the furnace gas valve closes. As a result, this cuts off the supply of gas to the pilot light.

How do I know if my gas control valve is bad?

If the burner stays on, turn the gas supply off and replace the gas valve. If the pilot is lit, you have a tank of cold water, the thermostat turned up and the burner does not fire up, either the burner orifice is clogged or the water heater gas valve is bad.

What causes a gas valve to fail?

The valve itself may have simply worn out or may be damaged due to basement seepage or submersion. Alternately, one of the electronic gas ignition components or a glitch in the safety circuit may be to blame. If your furnace has a standing pilot light, the thermocouple could be worn out.

How does gas control valve operate?

The gas control valve allows the pilot to be ignited, and the lit pilot heats the thermocouple. Once the water heater thermocouple is heated, it sends a signal to the gas control valve which allows the burner to operate, heating the water in the tank.

How does a gas valve work without electricity?

A small wire connects it to the gas valve. A pilot light, or a very small gas flame, heats one end of the thermopile. … Without being supplied millivolts of electricity, the gas valve cannot open and will remain in the closed position.) A pilot light has two functions.

What opens a gas valve?

The furnace gas valve operates by electromagnets. … The thermocouple (or thermopile) generates the power holds the safety valve open. Additionally, the thermocouple remains immersed in the pilot light flame. Without adequate heating of the thermocouple or thermopile, the furnace gas valve closes.

How do you test a gas control valve?

1. Turn off the furnace at the wall control. …
2. Take out the bolts in the service panel on the side of the furnace using a nut driver. …
3. Pull the wires off the gas valve terminals. …
4. Turn the test control on the multimeter to “mV,” which stands for millivolt.

Which way is gas valve on?

The long side of your handle is parallel to the incoming gas line, which means your gas in on and flowing. By turning the handle perpendicular to the incoming pipe, you are closing the valve and shutting off the gas.

How do I turn off the gas valve in my house?

There is a shut-off valve running parallel with the pipe, usually located about 6 to 8 inches above the ground. Take a 12-inch or larger adjustable wrench, and turn the valve 1/4 turn in either direction, until the valve is crosswise to the pipe. (See Diagram B)

How do you reset the gas valve on a furnace?

1. Turn the circuit breaker off and switch the furnace power button off too. …
2. Access the pilot light by removing the access panel. …
3. Turn the gas control valve off and let the gas dissipate for five minutes before turning it back on in order to prevent a fire hazard.

Article first time published on

How do you turn on gas logs without electricity?

Gas fireplaces that are more recent have an electronic ignition system that needs a spark of electricity to bring the appliance to life with a crackling fire. If you have a newer model, you can buy a backup, battery-powered igniter to fill your space with heat and light when the power is out.

Can you manually light a gas fireplace with electronic ignition?

It’s easy to know how to turn on a gas fireplace with an electronic ignition wall switch. Many gas fireplaces come equipped with a wall switch control panel for activating the unit and adjusting the level of the flame. Simply push the “On” button and the pilot should ignite.

How do you free up a stuck gas valve?

Heres how; First, turn off the gas in the house so you don’t blow yourself up or cause a disaster, loosen the bottom nut, tap the bottom of the plug upward to loosen the tapered plug, remove the tapered plug, lubricate with a special gas valve grease , and re-install the plug, job done.

Why is my gas fireplace not getting gas?

Check your breaker box and reset any tripped breakers you come across. Gas Valves: Make sure that your gas valve is open and in the on position to ensure the flow of gas to your fireplace. This should be located in the firebox. If you have an older model, a key in the wall or floor should be nearby.

How long does it take to bleed air out of gas line?

While pressing the valve control knob in, press the igniter button repeatedly until the pilot ignites. This could take anywhere from one to 10 minutes to bleed air out of the lines as the gas starts to flow.

What are the symptoms of having air in the fuel line?

Air bubbles in a fuel line can lead to stalling, hiccuping or refusal to start. Keep your fuel lines free of air to help keep your car running smoothly. Air bubbles in a fuel line can lead to stalling, hiccuping or refusal to start. Keep your fuel lines free of air to help keep your car running smoothly.

Why is my propane fireplace not lighting?

If your fireplace has a conventional pilot light: Step 1 – Check the main valve to make sure the gas is turned on. … Step 3 – If gas is coming out of the pilot, but it still won’t light, clear away any gunk sitting between the igniter and thermocouple using a can of compressed air.

How do I know if my gas valve is open?

Gas shutoff valves When the long side of the nub or handle is parallel to the incoming gas line, it’s open and the gas is flowing. When it’s turned a quarter turn, perpendicular to the incoming pipe, it’s closed.

How do you know if a valve is open or closed?

Ball valves are perhaps the easiest valve to see if they are open or closed. If the handle on top is parallel to the valve, it’s open. Likewise, if the handle is perpendicular to the top, the valve is closed.

What happens when gas is shut off?

The main gas service shutoff valve can be turned on in an emergency. If you smell gas, see a broken gas line, or suspect a gas leak, don’t shut off the gas. If you shut off the gas, it may take a while for the service to come back on.

How does the gas company turn off your gas?

Find your appliance, or zone gas shut off valves This is typically a lever ball valve with a handle (often yellow). When the handle is in-line with the pipe, the valve is open and gas will flow to your appliance. To shut off the gas to the appliance, turn the handle 90 degrees so it’s perpendicular to the pipe.

Are gas valves directional?

They are non directional. Choose your direction from which way you want the valve to turn to operate it.

How do you tell if gas lever is on or off?

In order to tell if the valve is open or closed, the general rule is, if the handle is switched 90deg to the flow, it is off. As you can see from the diagram above, if the handle is in line with the flow path, it is on.

How do you tell if gas is on or off?

Each gas appliance should have a gas line running to it that will have a valve located just before the appliance. This valve will likely resemble the valves on your gas main and can be operated by turning the valve to sit either in line with the pipe when the gas is on, or perpendicular to the pipe when the gas is off.

What would cause a furnace to not kick on?

The Pilot Light (Faulty Ignition Sensor) The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite. This is typically the problem if you can hear your furnace click on but it does not fire up. … Turn up the temperature on your thermostat to see if your furnace will now fire up.

How much does it cost to replace a gas valve on a furnace?

$350 – $595, Installed Replacement of your furnace gas valve cost between $350 to $595 installed by an HVAC company near you. DIY gas valve replacement cost around $65 buying the part online and replacing it yourself.

Can you clean a gas valve on a furnace?

Turn off electrical power and shut the furnace gas valve. Use a medium-bristled brush to sweep content off each burner and sweep out the combustion chamber as best you can. Use a straw or compressed air to blow dust and dirt off the pilot light assembly or hot surface ignitor, as well as the flame sensor.

Does gas work during power outage?

When the power goes out, it is imperative to turn off the power supply to your gas heating system. … During a power outage, a gas heater working on a gas pilot light will continue to work even without electricity. However, a conventional water heater will no longer heat the water in the absence of a power supply.

Can I run my gas fireplace without the fan?

Can I Run My Fireplace Without the Blower? … A fireplace without a fan will still work safely and effectively utilizing radiant heat to warm up the room & home. During a power outage all wood and direct vent gas fireplaces, Inserts and stoves will continue to work safely producing radiant heat without the need for a fan.

How long can you burn a gas fireplace?

In short, you really shouldn’t let a gas fireplace on for too long—specifically more than three hours at a time.

What is a vertical pilot on a gas fireplace?

If you have a gas fireplace with a vertical pilot, it will light during a power outage because it does not require electricity to start the pilot flame. Most gas fireplaces incorporate a self-generating millivolt system using a thermopile.