How to Check the Furnace Gas Valve With a Multimeter
- Turn off the furnace at the wall control. Wait for the unit to cool if it has been in use.
- Take out the bolts in the service panel on the side of the furnace using a nut driver. ...
- Pull the wires off the gas valve terminals. Each wire is connected to a push-on clip that slides off the terminal.
- Turn the test control on the multimeter to "mV," which stands for millivolt.
- Hold each tester wand on the multimeter to one of the terminals on the gas valve. ...
How do I know if my gas fireplace valve is off?
This would affect every type of gas fireplace. Locate the gas valve. Turn on the switch. Listen for the valve to open. If you hear the valve open (click, clank, clunk, etc.), but don't hear or smell gas. The valve may be off.
How do you test a gas valve with a multimeter?
It’s a good idea to now double check the power situation by checking the voltage, too. Take your multimeter and set it to Volts AC (VAC) and place the probes on the connection between the wires and the gas valve (black to white, red to red).
How do I know if my gas fireplace is lit?
If you see a flame, it's lit. Light the pilot. Fireplaces use flame sensors (thermocouples, thermopiles, etc.), to determine if there's a flame. If the sensor goes bad, the system will not hold the gas valve open.
How do I know if my fireplace flame sensor is bad?
Fireplaces use flame sensors (thermocouples, thermopiles, etc.), to determine if there's a flame. If the sensor goes bad, the system will not hold the gas valve open. Disconnect the thermocouple from the system. Set multimeter to measure DC millivolts (mV).
How do you test a gas valve with a multimeter?
0:231:43How to test a boiler gas valve with a multimeter - YouTubeYouTubeStart of suggested clipEnd of suggested clipCheck your leads and place them from top to bottom pin. And across dolls you should read aMoreCheck your leads and place them from top to bottom pin. And across dolls you should read a measurable resistance stay on the top pin go to the next pin up again.
How do you test a gas control valve?
2:105:43How to test a Gas Valve - YouTubeYouTubeStart of suggested clipEnd of suggested clipNext we're going to take some jumper wires. We're going to attach them to the gas valve. Now thisMoreNext we're going to take some jumper wires. We're going to attach them to the gas valve. Now this should only be done for one to two seconds just to check the operation of the gas valve.
How do I know if my gas fireplace valve is bad?
If there is no change in potential when the main valve is activated, then there is a fault or an interrupter may need to be reset. A very small drop in potential may be a sign that the main control valve needs replacement. A digital multimeter can also be used to test the main control valve.
How many ohms should a gas valve have?
Test the coils with an ohmmeter with the wires disconnected (you only need to disconnect one wire on each coil) and you should get around 40-60 Ohms resistance at the two leads of each coil. If the meter reads much lower or much higher then the coil is bad and needs to be replaced.
How do I know if my gas valve is working?
1:428:44The simple check of the gas valve - YouTubeYouTubeStart of suggested clipEnd of suggested clipBecause it's two stays that means there are two valves in the gas valve. And. So you have to checkMoreBecause it's two stays that means there are two valves in the gas valve. And. So you have to check the correct one okay the easiest way to do this checking is you don't get too.
How do I free 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.
How do you test a gas valve solenoid?
0:592:30Dryer Won't Heat? Gas Valve Coil Testing, Troubleshooting - YouTubeYouTubeStart of suggested clipEnd of suggested clipWhen testing a two-terminal coil. Use a probe to touch one of the coils terminals. And the secondMoreWhen testing a two-terminal coil. Use a probe to touch one of the coils terminals. And the second probe to touch the other terminal.
How much does it cost to replace a gas fireplace valve?
Furnace gas valve prices are $75 to $300 for the part alone or up to $600 for original manufacturer parts (OEM). Gas valve replacement labor costs $125 to $500....Furnace gas valve replacement cost.National average cost$500Minimum cost$125Maximum cost$1,000Average cost range$200 to $800Dec 27, 2021
Why is gas not flowing to gas fireplace?
One common issue after the off season is to have air in the pilot tubing. If you suspect this might be the problem, hold the pilot button down for about three minutes. This allows the air to bleed out of the line and should restore gas flow and allow the light to function.
How do you test a gas valve with a manometer?
11:2615:10Using a Digital Manometer to Set Furnace Natural Gas PressureYouTubeStart of suggested clipEnd of suggested clipTowards the end and towards the outlet and they are tagged on the valve itself. That's gonna be aMoreTowards the end and towards the outlet and they are tagged on the valve itself. That's gonna be a little bit different than checking the gas pressure than on the old valve.
Can a gas valve be repaired?
In some instances you can repair a gas valve on a furnace depending on what is causing it to not work properly. However, repairing your gas valve is not usually the most cost effective option since it can be just as expensive to have your gas valve repaired as it would be to have your entire gas valve replaced.
How does a gas fireplace control valve work?
Gas flows into a series of valves attached to your gas fireplace. The valves are always closed unless something opens it. This prevents gas from flowing into your home when the fireplace is not lit. A device called a thermocouple will hold open the pilot light valve as long as the pilot light is lit.
Where is the Gas Valve for my Fireplace?
This is where a knob that controls gas flow can be turned on or off. Typically, the gas valve for a fireplace is found on the control panel.
How do you tell if the Gas Valve is On or Off?
To tell if it is on, check if the valve is either parallel or turned a quarter unit, so it is perpendicular. If the gas valve is parallel to the incoming gas line, it is on. If you want to stop the gas flow, turn the gas valve a quarter turn, perpendicular to the incoming gas line. In this position, the gas valve is off.
How to Turn off a propane or Gas Fireplace Valve?
Next, you will find a knob. Try to turn the knob to the off position for at least 5 minutes or rotate counter clockwise until ON unit is in 6 o’clock position.
Is a Faulty Gas Fireplace Valve Dangerous?
Yes, a faulty gas fireplace valve is dangerous. Gas leak in your house is dangerous and can cause fire, so you should never repair a gas fireplace problem yourself. This can be very dangerous. You should immediately call a professional and have them deal with the issue.
Do Gas Fireplaces need a Shut-off Valve?
Gas fireplaces require a shutoff valve. These are required by law and it must be located outside of the firebox. The law goes further, stating that each appliance is required to have shutoff valve separate from the appliance that must must be installed “upstream” on the walls other rooms from the device it serves. If you are a fraid on accidentally turning on the fireplace, you could turn the gas shutoff unit for the fireplace.
What does a flame sensor do in a fireplace?
Fireplaces use flame sensors (thermocouples, thermopiles, etc.), to determine if there's a flame. If the sensor goes bad, the system will not hold the gas valve open.
How to read a thermocouple?
Connect the black lead to the button of the thermocouple. Connect the red lead to the copper part of the thermocouple. Heat the thermocouple with a torch. As the thermocouple heats, you should get a reading on the multimeter.
What happens if you don't hear the gas ignitor?
If you don't hear the ignitor- stop (you may have an electrical issue). If a strong smell of gas develops- stop (you may have a problem with the gas supply equipment). In most locales you can call your gas utility supplier and tell them "I smell gas" and they will come and take a look at the appliance for free.
How to test continuity of a switch?
Test: Label and remove the wires from the switch. Test continuity across the switch, in both positions. When the switch is toggled on way, you should measure infinity (or not hear a beep). When the switch is toggled the other way, you should get a measurement (or hear a beep).
Can a wall switch turn on a fireplace?
The wall switch will not turn the fireplace on if the pilot is not lit. Here is some general information regarding how gas appliances work (the source link below also has some pictures): Most gas appliance will have a gas valve, a thermocouple, a thermopile, a piezo, and a pilot light.
Do you have to have gas when you get gas from a tank?
If you get your gas from a tank or bottle, you'll want to make sure you have gas.
Can you hear a gas valve open?
See test for Gas Valve Closed. You won't hear the val ve open. You'll have to be sure the valve is getting the signal to open, so make sure all other items check out first.
How to check if furnace is working?
Take your clamp meter and clamp one of the wires. Observe the display on the meter as you start the furnace. If it reads 0.0, you should try clamping the other wire and read again.
What is a gas valve?
The gas valve is a critical component within the furnace’s inner workings. As with any valve, your furnace gas valve opens and closes to provide a flow of gas to the pilot light and to the burners. You will only find furnace gas valves on gas powered forced air systems – so if you’re running a different kind of furnace, this article isn’t for you!
Why does the main gas valve close?
This ensures that if a problem is detected at any point in the system, the main gas valve will close to prevent dangerous gas leaks. When the thermostat indicates that the home is below the desired temperature, the main valve opens and closes in order to meet the demand and maintain the set temperature.
What is the main valve in a furnace?
The main, or secondary, valve, is responsible for the supply of gas to the burner heads. This is the valve that the majority of this guide will be referencing. Modern furnace gas valves are actuated with electromagnets for opening and closing. To operate the electromagnets, a thermocouple is mounted within the flame of the pilot light.
How many gas valves does a furnace need?
Your furnace actually requires two separate gas valves in order to operate. The two are located next to each other, but take on different tasks. The first, or primary, valve we’ll talk about is the safety valve. This particular valve is responsible for the gas supply to the pilot light. The main, or secondary, valve, ...
What to do if your stove doesn't run?
The simplest way to do this is to test any other gas powered appliances in the home; if your stove runs, you’ve got gas to the home. If it doesn’t that’s a whole other story, and you’re probably going to need to call in professional help.
How many volts should a meter read?
Within about three seconds of the call for heat, you should see the meter reading around 24 volts.
Equipment to be Used
The good news is that much of this equipment and tools can be repurposed. That could be used for other tasks around the house as well.
Testing A Gas Valve on A Furnace: 5 Step Guide
On winter days, we become so obsessed with the gas furnace venting options that we forget about the gas valve’s well-being itself. This could be because the furnace shows a slow showing fault and we end up never noticing it.
Conclusion
I hope this answers your queries on how to test a gas valve on a furnace. This was my best take on this topic and I wish you could follow through the steps.
What is a normal gas valve reading?
A normal reading will be in the range of 145 to 195 millivolts. Readings outside this range indicate the gas valve is defective and must be replaced. Furnace gas valves cannot be repaired. James Clark began his career in 1985.
How does a furnace gas valve work?
Furnace gas valves are wired to an electronic component known as a solenoid, which receives signals from the thermostat control. This causes the gas valve to widen or narrow in front of the pilot light to respond to changes in building temperature. For example, if the temperature in your house falls below the setting on the thermostat, such as 68 degrees Fahrenheit, the gas valve opens to activate the furnace and produce more heat. When the building reaches the desired temperature, a separate signal causes the gas valve to close. Testing with a multimeter lets you know the valve works.
What does mV stand for on a multimeter?
Turn the test control on the multimeter to "mV," which stands for millivolt.
