Using a digital multimeter, turn it to the millivolt (mV) scale on the DC voltage range. With the alligator clip wires in place on the meter lead ends, clip one test wire to the gas valve (source) and the other one on the exposed copper wire leading to the thermocouple.
How do you test a gas valve with a multimeter?
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. A normal reading will be in the range of 145 to 195 millivolts.
How do I troubleshoot a gas valve on my Honeywell appliance?
Troubleshooting the valve and looking for known common issues will give you peace of mind by ensuring the safe operation of your Honeywell appliance. Turn off the gas supply valve to your appliance to test whether your valve is capable of shutting down properly.
How to test a gas meter for continuity?
Touch the two leads together from the meter, and you should get a reading close to zero. With the leads apart, you will read infinity. That is simply a test to check the meter for continuity. Finally, NOW TURN THE METER TO VOLTS.
How to test a multimeter thermocouple?
MultiMeter Thermocouple Test Procedure. First, remove the thermocouple. Secondly, turn on the meter and set it to Ohms. Touch the two leads together from the meter, and you should get a reading close to zero. With the leads apart, you will read infinity. That is simply a test to check the meter for continuity. Finally, NOW TURN THE METER TO VOLTS.
What is a normal gas valve reading?
Where is the gas valve on a furnace?
How do you test a Honeywell gas control valve?
28:2430:08Troubleshoot Water Heater AND Honeywell Gas Valve | Step-by-StepYouTubeStart of suggested clipEnd of suggested clipStart continue holding the temperature knob for about 30 seconds to allow the gas to flow throughMoreStart continue holding the temperature knob for about 30 seconds to allow the gas to flow through and heat up that thermal pile to operate the control board in this gas. Valve we should see a light.
How many ohms should a gas valve read?
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 you check for a bad gas valve?
How to Check the Furnace Gas Valve With a MultimeterTurn off the furnace at the wall control. ... 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. ... Turn the test control on the multimeter to "mV," which stands for millivolt.More items...
Can you ohm out a gas valve?
1:021:58What You're Missing When Ohming a Gas Valve - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo can you own a gas valve valve for troubleshooting. And the answer again is no you cannot becauseMoreSo can you own a gas valve valve for troubleshooting. And the answer again is no you cannot because you're actually not reading the coils. Themselves inside the gas valve.
How do you test a gas valve with a multimeter on a furnace?
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). Within about three seconds of the call for heat, you should see the meter reading around 24 volts.Jan 2, 2022
How many volts do you need to open a gas valve?
Modern gas valves typically have a printed circuit board in them that receive a 24-volt signal to activate the valve inside of it.
How do you test a gas valve with a manometer?
1:374:23How to Measure Gas Pressure on Modulating Gas Valve - YouTubeYouTubeStart of suggested clipEnd of suggested clipFirst we want to take the positive side of the dual port manometer. And connect to the manifoldMoreFirst we want to take the positive side of the dual port manometer. And connect to the manifold pressure tap on the gas valve. And that's located here.
How do you test a gas solenoid valve?
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.
What causes a gas valve to go bad?
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 a Honeywell gas valve work?
The Smart Valve system uses a 24 VAC powered hot surface pilot gas igniter to ignite the pilot gas. The main gas is ignited in both instances by a pilot gas burner. The Smart Valve system is self-contained, thus eliminating the need for a separately mounted ignition source, usually in the furnace or boiler vestibule.May 3, 2013
How to check if gas valve is shutting down?
Step 1. Turn off the gas supply valve to your appliance to test whether your valve is capable of shutting down properly. Set the thermostat or the device's controller slightly above the current room temperature. Loca te the hot surface igniter and look for a spark or glow there.
Why is gas valve bad?
Because gas is involved, problems with gas valves are a major safety concern. A stuck valve could release gas into the air without regulation or the valve could cause the unit not to fire up at all.
Can a Honeywell gas valve go bad?
Proper gas valve adjustment can save your home from a devastating fire. A bad gas valve in a Honeywell appliance such as a water heater or furnace that is powered by natural gas can go bad and affect the performance of the unit. Because gas is involved, problems with gas valves are a major safety concern. A stuck valve could release gas ...
How to test thermocouple with multimeter?
How to Test a Thermocouple with a MultiMeter. If you test the thermocouple with the multimeter and you get a reading above 25, then you have another issue. Importantly, always make sure the tip of the thermocouple is directly in the pilot flame. If the tip is in the flame, you have held the nob on the gas valve down for longer than a minute, ...
How many millivolts should a pilot gas valve be?
Finally, if the reading is less than 25 millivolts replace the thermocouple as most standing pilot gas valves need 25 or more millivolts to keep the pilot flame lit. The thermocouple millivolt range should be above 25 millivolts. If so then it is good.
What is the tip of a thermocouple called?
That provided a means of proving the main burners would ignite when the main valve opened. The tip of the thermocouple is called the hot junction and is where the two dissimilar metals join. A weld joins the two metals. The other part of the thermocouple tip is called the cold junction.
How does a thermocouple produce millivolts?
From the cold junction, a stem runs in length from the main body of the thermocouple tip to the gas valve. When the heat hits the hot junction or tip of the thermocouple, it produces millivolts. This fractional voltage energizes a small solenoid designed for millivolts.
What is a standing pilot gas valve?
In the early 1900s, Honeywell applied it to the safety gas valve. A standing pilot gas valve has two inner valves, one for the pilot light and one for the main valve. If the pilot valve is closed the main valve would not open. The thermocouple was used to hold the pilot valve open.
What is a thermocouple?
A thermocouple is a safety device for a standing pilot gas system. Originally, it had a ratio of copper and nickel and was labeled a Coppel ( Copper/Nickel) element. Thomas Seeback discovered it in 1821. In the early 1900s, Honeywell applied it to the safety gas valve.
How to read infinity on a thermocouple?
First, remove the thermocouple. Secondly, turn on the meter and set it to Ohms. Touch the two leads together from the meter, and you should get a reading close to zero. With the leads apart, you will read infinity. That is simply a test to check the meter for continuity. Finally, NOW TURN THE METER TO VOLTS.
Why is it important to know how to test a thermocouple?
Even though they are fairly cheap to replace, it’s important to know how to test a thermocouple to expose any other problem areas beyond the part itself. Knowing how to perform even a simple function test can give you a good idea whether your appliance just needs an inexpensive repair, or a more costly fix is in order.
What is a thermocouple?
A thermocouple is a type of electrical device know as a transducer, and in various forms, is found in everything from small toasters to massive industrial kilns. It basically converts the temperature it senses into a certain measure ...
Can you use soapy water to check for gas leaks?
Extra care should taken when reconnecting the thermocouple fittings to prevent any cross-threading. To be sure there are no gas leaks associated with an improperly tightened fitting, you can use soapy water to check for any bubbles after the gas is turned back on.
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.
Where is the gas valve on a furnace?
The gas valve is inside the furnace cabinet. Image Credit: Jupiterimages/Comstock/Getty Images. 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.
