How to tell if Ignitor is bad?
Taking a thorough look at the ignitor
- Begin with turning off the furnace at the electrical switch placed on its side. The button looks like a regular light switch.
- Identify the ignitor; typically is in the upper right. It features a white base with a black part going into the furnace port.
- Once you’ve spotted the ignitor, you will also have to remove the screw/screws that keep it in place.
How to troubleshoot a thermocouple?
How to Troubleshooting Thermocouples on Gas Fired Heating Equipment First confirm that the problem is the thermocouple Typically the gas control is pushed-in or held in a spring-loaded position to force gas through the pilot light assembly to permit manually lighting the pilot flame.
Can a thermocouple go bad?
What makes a thermocouple go bad? Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break. If thermocouples start to give out unusual readings, it may be suffering from metal fatigue.
How do you fix a water heater thermocouple?
- Before you begin, be sure to unplug the water heater’s power cord and shut off the gas supply.
- If necessary, unthread any mounting screws and remove the burner access cover.
- Next, unthread the nuts or screws securing the burner plate itself.
- Unthread the nut to detach the burner supply tube from the gas or control valve. ...
How do you know when you need a new thermocouple?
A bad thermocouple itself can prevent a gas furnace or boiler from working - if you can light the flame at the pilot manually but then the flame goes out when you release the manual gas feed valve, the thermocouple is probably bad.
What happens when a thermocouple fails?
Normally when the thermocouple malfunctions or isn't working, it simply shuts off the gas to your heater. This is important, particularly if the pilot light is out, because it prevents harmful gas from leaking into your home.
How do you diagnose a bad thermocouple?
Hold the reset button between 30 to 60 seconds to give the thermocouple time to heat up. Release the button to see if the pilot light goes out. The pilot light should stay on after the reset. If it goes out, this is a sign that the thermocouple has failed.
Will a pilot light stay lit with a bad thermocouple?
The thermocouple is a safety device designed to shut off the gas valve if the pilot light goes out. Although, if your thermocouple is old, worn, damaged, wrongly positioned, or malfunctioning, it could be wrongly shutting off the gas valve as well as preventing your pilot light from staying lit.
How do you unclog a thermocouple?
Yes, you can clean a thermocouple, but the task must be done with a light touch. Remove the thermocouple from the process assembly, using a steel wool or emery cloth, lightly clean the tip removing any build up. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings.
How often do thermocouples need to be replaced?
Thermocouples can last up to 10 years if properly installed and maintained, while furnaces can last 15-20 years, although either may wear out sooner in multifamily units.
What causes thermocouple to go out?
Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break.
Can thermocouple burn out?
The most common failure mode for thermocouples is for them to fail open, this is known as thermocouple burnout. Burnout can result from a variety of reasons including the thermocouple experiencing a temperature in excess of that for which it was designed, metal fatigue, and oxidation.
How does a thermocouple get damaged?
OVERHEATING. There is such a thing as too much heat for a thermocouple. Whether you accidentally use a thermocouple that isn't meant to operate at your applications temperatures or your processed run hotter than they should, exposure to overheating can damage the elements in a thermocouple.
Should the flame touch the thermocouple?
The pilot flame should touch the thermocouple at a specific level. If the flame is blue and weak, and barely reaches the thermocouple, it needs to be stronger. If it extends well above the thermocouple, it's too strong.
What is the life expectancy of a thermocouple?
Thermocouple life expectancy varies greatly from just a few hours to many years. Many factors in- cluding calibration type, environ- ment, temperature, sensor design, and thermal cycling will determine life expectancy.
Can you touch a thermocouple?
A thermocouple produces a very small electric current. The electric current is produced by the heating of the special metal wires in the device. The thermocouple is not hooked up to any source of electric current and the amount of current it produces would not hurt you.
How much should a plumber charge to replace a thermocouple?
Thermocouple – $20 to $150 The thermocouple is an apparatus that senses whether the pilot light is lit and triggers the gas control valve. Repairs typically cost about $150 to have it done professionally, though a new thermocouple itself only costs about $20 on average.
What is the life expectancy of a thermocouple?
Thermocouple life expectancy varies greatly from just a few hours to many years. Many factors in- cluding calibration type, environ- ment, temperature, sensor design, and thermal cycling will determine life expectancy.
How do I know if my thermocouple is bad on my water heater?
If the pilot lights but the flame goes out as soon as you release the button after holding it for 60 seconds, then the thermocouple is bad. It's possible to replace the thermocouple without removing the burner assembly, and many repair people do this.
What would happen if a thermocouple is overheated?
If the back end of your thermocouple bulb gets constantly overheated, it will fail. With excessive back pressure coming from the burner ports, thermocouples can get burned up quickly. There are many types of thermocouples, most of which are interchangeable.
Ensure The Position And Sanctity of Thermocouple
A thermocouple is a sensor that calculates the temperature. It is being used in a broad range of applications. This device is manufactured in a variety of styles, models, and technical specifications.
How to Know If a Thermocouple Is Bad?
To operate correctly, a thermocouple requires the full heat from the pilot light. So that it can produce an ample amount of electrical flow. Yet, there are multiple causes behind the workflow being hampered.
What If The Problem Is Somewhere Else?
If the thermocouple isn’t bad, then what’s creating a problem? I know this is the first question that hits your mind.
Final Notes
Let’s be apart from here. I’ve explained everything regarding how to tell if a thermocouple is bad. Hopefully, you have understood how to find out the issue.
How Do You Know If You Have A Bad Thermocouple?
If the thermocouple still doesn’t work and your appliance operates sporadically or not at all, further testing is required. This procedure is a bit more involved and requires a voltage meter. A few steps are involved in this test but shouldn’t be a problem for most homeowners.
What Is A Thermocouple?
A thermocouple is a device that produces a small electric current when it is heated. The thermocouple has two dissimilar metals that form an electrical circuit. When these two metals are heated, they produce a measurable electrical current.
What to do if thermocouple doesn't work?
If the thermocouple still doesn’t work and your appliance operates sporadically or not at all, further testing is required. This procedure is a bit more involved and requires a voltage meter. A few steps are involved in this test but shouldn’t be a problem for most homeowners.
How to tell if a thermocouple is bad?
The easiest way to tell if you have a bad thermocouple is to do a simple test using a voltage meter. There may be other problems in your appliance that can lead to problems. Eliminating these possible issues should be done first. Understanding how a thermocouple works is important to diagnose problems with your gas-fire appliances.
What happens when a thermocouple is heated?
The thermocouple has two dissimilar metals that form an electrical circuit. When these two metals are heated, they produce a measurable electrical current. You gas appliance checks for this electrical current to make sure that the pilot light is working.
How to read a voltage meter?
Your voltage meter has two probes, one red and one black. Set your voltage meter to read voltage (V) in millivolts. Attach the red probe to the thermocouple and the black probe to the body of the gas valve. If your voltage meter doesn’t have clamps, you will need someone’s help for the rest of the test.
Why does my gas stove make a clicking sound?
You should hear a clicking sound as the igniter fires and then the burner should light. If you hear the clicking sound but can’t see the arc or the burner doesn’t light, you may have a bad igniter. Contact an appliance repair service to check the igniters. If you suspect other problems with your gas appliance, visit this article for more advice.
How Does a Thermocouple Work?
The thermocouple responds to changes in temperature by producing an electrical current that causes the gas valve that supplies the pilot light to open when the temperature is high or to close when there is no direct heat source.
How to test a thermocouple?
Step 2: Open circuit test of the thermocouple 1 Before the test, turn off the gas supply because you must first remove the thermocouple. 2 Remove the thermocouple by unscrewing the copper lead and connection nut (first) and then the bracket nuts. 3 Next, take your meter and set it to ohms. Take the two leads from the meter and touch them—the meter should read zero. Once this check is done, turn the meter back to volts. 4 For the actual test, turn on your flame source, and place the tip of the thermocouple into the flame, leaving it there until it is quite hot. 5 Next, attach the leads from the multi-meter to the thermocouple: put one on the side of the thermocouple, and attach the other lead at the end of the thermocouple that sits in the pilot light. 6 A working thermocouple will give a reading of between 25 and 30 millimeters. If the reading is less than 25 millimeters, it should be replaced.
What is a thermocouple made of?
The thermocouple is made up of a tube, a bracket, and wires. The tube sits above the bracket, a nut holds the bracket and wires in place, and underneath the bracket, you will see the copper lead wires that connect to the gas valve on the furnace.
How many millimeters does a thermocouple read?
A working thermocouple will give a reading of between 25 and 30 millimeters. If the reading is less than 25 millimeters, it should be replaced.
How to inspect a furnace thermocouple?
How to Inspect Your Furnace’s Thermocouple. You will need a wrench, multi-meter, and a flame source, like a candle or a lighter, to perform the test.
How to tell if a thermocouple is failing?
Once you have located the thermocouple, do a visual inspection. You are looking for a few things. The first is signs of contamination on the tube , which can include discoloration, cracks, or pinholes.
Why visually inspect connectors?
Finally, visually inspect the connectors for physical damage because a faulty connector can affect the reliability of the test reading.
How to read millivolts on thermocouple?
Set the multimeter to read millivolts, then start the pilot and have your helper hold in the gas control knob to keep it burning. After about a minute, when you’re sure the probe has gotten hot, place one lead on the shaft of the thermocouple and the other lead on the connector.
Why won't my thermocouple stay lit?
This is the result of a phenomenon known as the Seebeck Effect. Nothing lasts forever, and when the thermocouple wears out, the pilot won’t stay lit and your appliance won’t work. The pilot can go out for a number of other reasons, however, so if you’re having trouble getting the pilot to stay lit, the thermocouple may not be at fault.
How does a thermocouple work?
It does this by sending a tiny electric current to a sensor on the gas valve signaling the valve to stay open . The thermocouple can do this because, in its probe, it contains two different metals, and a voltage is generated when one of them is heated. This is the result of a phenomenon known as the Seebeck Effect.
Why won't my water heater pilot light?
The procedure for lighting a standing pilot always includes lighting the flame, then manually holding in the gas valve to keep the flame burning and give the thermocouple time to heat up. If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube.
How long does it take for a thermocouple to go out?
If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds , that’s the sign of a thermocouple malfunction. Before jumping to the conclusion that the thermocouple is at fault, look at the pilot flame.
What is the job of a thermocouple?
The job of the thermocouple is to keep the pilot lit. It does this by sending a tiny electric current to a sensor on the gas valve signaling the valve to stay open. The thermocouple can do this because, in its probe, it contains two different metals, and a voltage is generated when one of them is heated. This is the result of a phenomenon known as the Seebeck Effect.
How to light a standing pilot?
The procedure for lighting a standing pilot always includes lighting the flame, then manually holding in the gas valve to keep the flame burning and give the thermocouple time to heat up. If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube.
How to remove thermocouple from thermostat?
Remove the thermocouple with a wrench. Go back to the thermostat and locate the metal nut holding the thermocouple in place. Use a 7⁄16 in (11 mm) wrench to rotate the nut counterclockwise and free the thermocouple. Turn on the multimeter.
How to check if thermocouple is at fault?
To double-check that the thermocouple is at fault, look at the dial to locate a position labeled “Off.” Spin the dial to shut off the gas supply. If this isn’t possible, follow the metal pipe leading into the pilot light controls. It will have a small valve on top of it. Turn the valve counterclockwise to stop the flow of gas.
What does it mean when a thermocouple is white?
If your thermocouple is coated with a white, chalky material, this may indicate it's not functioning properly. [15]
Why does the pilot light stay on after the reset?
The pilot light should stay on after the reset. If it goes out, this is a sign that the thermocouple has failed. You can replace it right away or remove it to perform a more accurate test.
How to measure resistance?
For the test, the type of multimeter with red and black clamps is easiest to use. Flip on the multimeter’s power switch. Spin the settings dial to change the measurement to Ohms, represented by the horseshoe-shaped symbol . This is used to measure electrical resistance.
What is a thermocouple?
A thermocouple is a safety device that helps control the gas supply in gas-heated furnaces. When it stops working, the furnace’s pilot light also turns off. For a basic test, attempt to turn on the pilot light again. If you’re still unsure or don’t have a working pilot light, test the thermocouple with a multimeter.
How to test a multimeter?
Test the multimeter by holding the leads together. Hold the black and red clamps, or leads, apart. When you point them in opposite directions, the meter should stay to the left at infinity. Bring the leads together and watch as the meter changes to 0.
Ensure The Position and Sanctity of Thermocouple
How to Know If A Thermocouple Is Bad?
- To operate correctly, a thermocouple requires the full heat from the pilot light. So that it can produce an ample amount of electrical flow. Yet, there are multiple causes behind the workflow being hampered. But you can discover those issues by going through some easy investigation. Here I’ve shown a 5-step method to find out if your thermocouple i...
What If The Problem Is Somewhere else?
- If the thermocouple isn’t bad, then what’s creating a problem? I know this is the first question that hits your mind. Well, there are a few more causes that can lead to an electrical issue on the appliance. It can be a pressing problem in your gas-fired heater. An aged heater can create issues with gas valves, control panels, or even burners. A damaged heater can turn on the gas oven aut…
FAQs
- Question: Can I clean my thermocouple? Answer: Definitely, you can! Though you have cleaned the device with a soft hand. Use any type of steel wool or emery cloth to wipe off any dirt. But cleaning the device won’t fix any technical issues. Question: How do you bypass a thermocouple? Answer: Unscrew the tilts switch wire. Use an 8mm wrench to pull off the thermocouple. Take of…
Final Notes
- Let’s be apart from here. I’ve explained everything regarding how to tell if a thermocouple is bad. Hopefully, you have understood how to find out the issue. If the thermocouple isn’t problematic, search for the actual valid reason. Such as the gas heater, auto ignitor, and pilot light. Meanwhile, don’t forget to maintain safety measures. Until next time, take care!