In this task, youll need to heat the thermocouple. If a thermocouple tests at 25 millivolts or lower, it doesnt have the power to keep a pilot lit and it should be replaced. Then, when the pilot is burning brightly, release the reset button. "Very clear and simple drawings make it easy to learn the basics in a short time. Special Offer on Antivirus Software From HowStuffWorks and TotalAV Security. You may have to wiggle it a bit before it comes loose. Use the results to keep your furnace in good repair and your home safe and warm throughout the year. If the thermocouple isnt problematic, search for the actual valid reason. While buying the voltmeter, try to get one with the clamps. A few quick steps can have your gas appliance back in operation. Check the following: 1. This instrument contains two probes; red and black. Whatever you do, never use any cleaning products or liquid of any kind. I checked that, and found zip - no voltage at all from the thermocouple. Replace the furnace access cover and test the furnace operation by changing the thermostat settings to make sure the furnace turns on and off properly. The thermocouple may get faulty if dirt builds upon and around it. They will replace the thermocouple when they do this. To replace a thermocouple: Step 1: Unscrew the copper lead and the connection nut inside the threaded connection to the gas line. A working thermocouple will give a reading of between 25 and 30 millimeters. Call for details. Since no flame is required to burn all the time, auto-igniters are less expensive to operate. The Red wire is generally the negative (-) wire in thermocouples, harnesses, and cables. Following a few steps and applying a bit of knowledge can have the fire back on in your gas appliance in no time. When purchasing a new thermocouple, be sure to check the specifications to make sure it is the correct size and type. Separate the thermocouple connector from the gas valve. Remove the thermocouple from the process assembly, using a steel wool or emery cloth, lightly clean the tip removing any build up. Turn the gas valve on the appliance to the Light Pilot setting. To do this, youll need a voltmeter with a thermocouple probe. Pilot hood and flame direction. Replacing a thermocouple is a relatively easy fix that can take less than two hours. Step 3: If the pilot flame won't stay lit after several tries, it should be adjusted by a professional. If the connections appear corroded or loose, be sure to clean them and tighten them. How to know if a thermocouple is bad? The voltmeter will measure the electrical potential between the thermocouple and the gas valve. Its because of the dirt build-up inside the igniter. And put off the thermocouple connector from the gas valve. If the igniter has a pilot hole, move a sewing needle carefully around inside the hole to loosen any trapped material. The actual thermocouple on mine is just a bare metal ball. Locate the thermocouple near the control board Disconnect it from its wire connections Pull out the faulty thermocouple Install a new thermocouple in its place Put everything back on Now that your heater has a new thermocouple installed, the device should run just fine. As mentioned before that this device will convert thermal energy to electrical energy. If it is mashed or one of the wires is broken off right at the thermocouple then youre going to have get a new one - that kind of thing cant be fixed. The thermocouple on a gas fireplace may eventually become clogged with dirt and soot, which can reduce the effectiveness of the thermocouple and may eventually prevent the fireplace from lighting as expected. Then attach the black clamp to the gas valve. If you have gas-fired appliances such as a water heater, space heater, or cookstove, these appliances may have one or more thermocouples. If it is short and blue, then it is too weak. Sometimes the sporadic movement of the thermocouple can also shake its position. Before the test, turn off the gas supply because you must first remove the thermocouple. Maybe itll help, maybe it wont. If finding that the thermocouple does not read, the problem is most likely a bad connection, broken wiring, or open internally within the thermocouple probe circuit. If so, strip back some of the insulation, cut both bare wires to the same length, and reattach the wires. If you properly maintain your appliance and thermocouple, the thermocouple can last about 10 years. Be cautious when reinstalling the thermocouple. If the resistance measurement shows an open circuit, look closely at the thermocouple itself. This is often not realized and overlooked during troubleshooting. After three minutes, turn the valve to the PILOT position. Next, take your meter and set it to ohms. If your furnace pilot light won't stay lit, then it might be an easy fix.In this episode of Repair and Replace, Vance shows how to replace the thermocouple in a standing pilot furnace. Sounds exciting right? If the flame goes out repeatedly, it may be getting too little air; if it's yellow at the tip, it's getting too much air. Enjoy! Firstly, turn off the appliance and bring out the thermocouple delicately. You'll need a lint-free cloth, some emery cloth sandpaper, and a screwdriver. But cleaning the device wont fix any technical issues. How To Replace Thermocouple On Gas Water Heater? An old toothbrush is a perfect tool for this job. Set the multimeter to read millivolts, then start the pilot and have your helper hold in the gas control knob to keep it burning. If you cannot see or detect problems proceedwith the test. A thermocouple is a device that produces a small electric current when it is heated. You are looking for a few things. If there is a safety or reset button, push the button, and keep it depressed. A functioning thermocouple should also show a few millivolts DC when hot. Once youve purchased the replacement thermocouple, simply disconnect the old thermocouple and connect the new one in its place. Expert help is available online, over the phone or in person at one of the many locations across Canada.Connect with AMRE SupplyWebsite - https://www.amresupply.com/Facebook - https://www.facebook.com/amresupplyTwitter - https://twitter.com/amresupplyInstagram - https://www.instagram.com/amresupply Finally, its important to properly maintain your thermocouple to ensure it works correctly for a long time. 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. The wiring should also be inspected, as contamination on the surface of the wire can greatly reduce the accuracy of the temperature. It does not constitute professional advice. Last Updated: October 25, 2022 In most cases, the thermocouple attaches to the gas valve with a thin. Gas appliance thermocouples have a standard design. Use the chart below to make sure that the positive and negative connections are in the proper order. 2 An exposed junction thermocouple offers the fastest response. If the connections appear loose or corroded, then you will need to clean them and tighten them. You should hear a clicking sound as the igniter fires, and then the burner should light. Step 2: Under the mounting bracket at the thermocouple tube, unscrew the bracket nut that holds the tube in place. Locate the thermocouple on the gas control thermostat. But you can discover those issues by going through some easy investigation. Who wants to get burnt or experience a shock? In that case, you have to replace a new thermocouple. Your email address will not be published. The first step in repairing a thermocouple is to identify the problem. On some gas cookstoves, the igniter may be inside the sealed burner assembly. Please copy/paste the following text to properly cite this HowStuffWorks.com article: Fix-It Club If you have a K-type thermocouple that came with your multimeter or if you bought one of the many cheap K-type thermocouples from Amazon or wherever, it may some day quit on you. To test the thermocouple, it must be hot. Use a can of compressed air to gently blow away any dust and dirt from the thermocouple. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings. When cheap crap breaks and ordering a replacement will take too long. Another option is to call a heating repair person near you. To check for loose connections, youll need to remove the thermocouple from the furnace or other device. Multiple connections should be avoided in order to improve accuracy. 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. To examine the gear, youll need a voltmeter. You might also get a splatter or crumb of solder or other metal between them. By creating an account you agree to the Hunker, How to Change a Thermocouple on a Fireplace. A quick look at Amazon and other places showed Id be waiting a couple of weeks for one to be delivered, so I decided to take a closer look at the thermocouple. If youre still unsure or dont have a working pilot light, test the thermocouple with a multimeter. Finally, we will count the voltage level in the upcoming segment. If you have a gas water heater, gas wall heater or any other appliance with a gas burner that needs to cycle on and off, there's a thermocouple in your life. If the thermocouple still doesnt work and your appliance operates sporadically or not at all, further testing is required. To bypass the thermocouple: Move the tilts switch wire aside. Your furnace pilot light should burn just fine if you have got all these steps right. Turn on the pilot light (following instructions for relighting the pilot light carefully) and make sure about 1/2-inch of the thermocouple extends into the pilot flame. Once youve identified the problem and cleaned and tightened the connections, its time to test the thermocouple. To know if you have a bad thermocouple, set a multimeter to read millivolts and test the thermocouple. Take the two leads from the meter and touch themthe meter should read zero. Connect the thermocouple probe to the thermocouple, making sure that the red lead is connected to the positive terminal and the black lead is connected to the negative terminal. If you suspect other problems with your gas appliance, visit this article for more advice. Working with response times. Yes, you can clean a thermocouple, but the task must be done with a light touch. The auto-igniter then creates an electric arc to the burner, igniting the gas. Hunker may earn compensation through affiliate links in this story. Appliance Repair Expert. Use a lighter or torch to hold a flame under this end. Therefore, its always wise to practice proper maintenance and upkeep of your appliances. 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. Ive seen quite a few appliances require turning and holding the valve to control. A) Make sure the thermocouple is free of soot, centered in the flame of the pilot light, and is screwed in tightly to the control valve. The plug fit better and held tighter, but still no temperature. If your equipment calls for a J type, you will need to replace with a J type. You can also eliminate obstructions in the pilot tube as a possible cause by turning off the gas, unscrewing the pilot tube from the gas valve and blowing compressed air from a can through the tube. , it must be hot. The thermocouple doesnt have wires. A burned out or broken thermocouple should be replaced. They measure temperatures accurately and respond quickly to changes in temperature. By creating an account you agree to the Hunker, How to Change a Thermocouple on a Fireplace, How to Troubleshoot an Electronic Ignition for a Superior Gas Fireplace, Adjusting the Gas-to-Air Ratio on a Heat-N-Glow Fireplace. I know its really hard to tell if it has started to malfunction or not. If the appliance has a thermocouple, the problem may be a faulty thermocouple. By signing up you are agreeing to receive emails according to our privacy policy. Fortunately, the plug can be disassembled. 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. Remove the valve using your pliers. Mostly, they are connected through a thin copper tube. The thermocouple on your appliance is with the pilot light. Unhook Everything From the Gas Valve 03. Better to be safe than sorry. Your thermocouple voltage should be between 25mV and 30mV. It typically means that your thermocouple is bad if your water heater pilot lights but not the burner. Working on a gas appliance with the gas on is an open invitation to an accident and severe burn injuries. If all heater zones show continuity then check the resistance of each zone and compare it to the value shown on your hot-runner. A damaged heater can turn on the gas oven automatically. It might be broken, but theres a better than fair chance that it is just shorted out. Include your email address to get a message when this question is answered. Fireplace How To: Testing A Thermopile - YouTube 0:00 / 3:28 Fireplace How To: Testing A Thermopile Fire-Parts 2.52K subscribers Subscribe 1.3K 266K views 6 years ago For technical support, or if. Light green color, on a type K thermocouple indicates the occurrence of aging and a change in the chemical composition known as Green rot. link to Natural Ways To Keep Mosquitoes From Biting. When the flame is weak, boost up the flame to reach the device. At the. Absolutely you dont want that. The pilot light is a small open flame that is fed by a steady flow of gas. The following are the six most common causes of thermocouple measuring errors, followed by ways to rectify them: 1. Auto-igniters are quite simple. Sounds interesting? A few simple maintenance steps could have your igniter up and running again quickly. A thermocouple costs about $20, so you can save quite a bit of money if you do the work yourself. Look around the igniter as well and make sure there is no build-up on the burner or near the igniter. 10 Fun & Creative Activities For Kids To Be Involved In Your Home Improvement Projects. Just the fact that you have to shut down and replace a thermocouple means lost revenue. Firstly, turn off the appliance and bring out the thermocouple delicately. If so, unscrew them from the pins and untwist the wires. The thermocouple is made up of a tube, a bracket, and wires. An aged heater can create issues with gas valves, control panels, or even burners. Water Heater Maintenance: Extend Water Heater Life Step 2 Burner assembly Remove the burner assembly and detach the thermocouple. Cleaning the thermocouple is a pretty simple process but should only be done when the fireplace is turned off and is completely cool. Often the thermocouple connection points are overlooked, but are critical for proper readings. If the resistance measurement shows an open circuit, look closely at the thermocouple itself. Do You Need to Hire an Electrician? Note: Only clean an orifice with compressed air as drill bits and other abrasive items can enlarge the opening. The pilot light controls, reset buttons, gas valves, and thermocouple are usually contained in an assembly at the front of the furnace. A working thermocouple will produce a reading of 25 to 30 millimeters. If the thermocouple is working, you should be able to measure 30 to 40 millivolts of voltage at the connection end of the tube when the pilot flame is on. Must present coupon at time of service. Anyways, connect the red string to the thermocouple. Take the two leads from the meter and touch themthe meter should read zero. Start at the cable connector for the controller and work your way towards the tool. In any case, Ive been comparing the temperature at the tip of my new iron to the measured temperature on the display. Make sure that the wiring is protected with insulation and is not damaged or broken anywhere in the circuit. It is usually found near the system's pilot lights or burners. 2 May 2006. This goes for all calibrations. When the thermocouple is dirty, it won't produce enough voltage to open the gas valve, this will cause the pilot light to go out after you release the bypass button. I found that the display was fairly accurate with the original tip, but lost about 30 degrees celsius when using the fine tip I prefer. All you need to do is scrape the thermocouple clean and then dry-wipe the residue. Your voltage meter has two probes, one red and one black. By following the steps outlined above, you can easily repair a malfunctioning thermocouple and get your heating or cooling system back up and running in no time. If you find a dead short from pin to pin, check the inside of the plug and see if the wires are twisted. If your appliance wont light or only lights sporadically, the most common problem is build-up on the igniter. Nothing lasts forever, and when the thermocouple wears out, the pilot won't stay lit and your appliance won't work. Step 2: Hold a lighted match to the pilot orifice and turn the gas valve to the ON position. There are all sorts of methods out there. A time constant has been defined as the time required by a sensor to reach 63.2% of a step change in temperature under a specified set of conditions. Stocking the largest selection of appliance parts, heating, plumbing, lighting, and janitorial supplies, AMRE ships almost anywhere in Canada within 24 - 48 hours. Start the test by unscrewing the thermocouple from the gas valve. Meanwhile, dont forget to maintain safety measures. On his retirement, he started a remodeling and home repair business, which he ran for several years. In most cases, the thermocouple attaches to the gas valve with a thin copper tube. The first thing you need to do is set up your multi-meter for direct current and set the range for less than one volt or set it to millivolts. Reading the voltage level is the last step to find out the real cause. If there is no current from the thermocouple, the appliance will not let the gas valve open. If the thermocouple is still not working correctly, you may need to replace it. How to Remove the Thermocouple in a Heat & Glo Fireplace, Omega: Thermocouple: Different Types, What It Is, and How to Replace One, High Performance HVAC: How to Test a Thermocouple with a Multi-Meter. Thus, find out the control of the gas valve and switch it off immediately. With my old iron, I just cranked up the heat any time I felt like it wasnt hot enough. All information is subject to change at any time without notice. Finally, put back the thermocouple inside the box. Remember to be safe when doing repairs around your home. Caution: Some older appliances may not have a safety device to turn the gas off when the pilot is extinguished. Overtightening it can prevent the flame from lighting. Thanks to all authors for creating a page that has been read 100,018 times. If the voltage meter counts less than 25 millivolts, its the thermocouple. If the thermocouple doesn't function after cleaning it, it would be best to replace it with a new one. Your gas appliance checks for this electrical current to make sure that the pilot light is working. Remember that you are working around open flames. What does a thermocouple look like and how do you find it? This article was co-authored by Gevorg Grigorian. Like the other component parts in your furnace, the thermocouple can wear down over time, producing lower voltage than it should when heated. The No. Be sure to turn off the power to the device before attempting to remove the thermocouple. Others require that you push the gas valve in to open the valve to the pilot light. We use cookies to make wikiHow great. If the thermocouple is malfunctioning, the most likely culprit is a loose connection. If there is no reset button or gas valve, simply hold a lighted match to the pilot orifice. FIND LOCAL CONTRACTORS. A gas water heater in Boise, Baton Rouge, Buffalo or Boston uses a thermocouple that includes a probe attached to a copper tube that screws into a port on the gas valve. Once this check is done, turn the meter back to volts. If your thermocouple is coated with a white, chalky material, this may indicate it's not functioning properly. Some panels have a screw on each side that needs to be removed and other panels lower on a hinge. Fortunately, repairing a thermocouple is a relatively simple process that requires minimal tools and a bit of patience. In our final section, we will conclude our discussion of repairing major appliances with a detailed examination of -- of course -- motors. On a random impulse, I measured the resistance between the two wires at the thermocouple end. Did you know you can get expert answers for this article? Unscrew the thermocouple from the gas valve and have a helper hold the gas control knob to keep the pilot burning. Use a soft rag to wipe any residue from the igniter. If youre uncomfortable performing this test yourself, be sure to call a licensed HVAC contractor who can help you. 30 July 2020. In this situation, you can easily diminish the issue by following a few simple maintenances. 1 cause of pilot lights that won't stay lit is a worn-out thermocouple. By using our site, you agree to our. Cannot be combined with other offers. On other units, remove the panel that covers the pilot and gas burners. 1 millivolt is equal to 1/1000 of a volt. Carefully complete a thorough inspection of the thermocouple probe looking for any pin holes, cracks, and areas with discoloration indicating internal contamination issues. Dennis is a retired firefighter with an extensive background in construction, home improvement, and remodeling. I understand this seems quite confusing for you. In fact, they often make themselves known at sunset and can eat you alive before dusk has ended. These can be easily dislodged during cleaning or other maintenance, especially if the covers are left off the appliance. How To Replace Thermocouple On Ge Water Heater, Your email address will not be published. References. Just swap the two wires and itll be OK. A little poking around saved me a few bucks and a couple of weeks worth of waiting for a new thermocouple. It may have gotten crushed or one of the wires may have broken off. The thermocouple, which operates as a safety device, turns the gas supply off when the pilot light goes out. Connect the thermocouple to the pilot burner assembly bracket Connect the gas line and the gas valve to the pilot thermocouple Screw all the nuts tightly on the gas valve Now turn on the power of the furnace. I can solder wires with the fine tip just fine at 260 degrees celsius, but it takes about 300 degrees to do SMD parts. Set your voltage meter to read voltage (V) in millivolts. This device is manufactured in a variety of styles, models, and technical specifications. Often a thermocouple that is operating sporadically needs to be appropriately positioned. (J, K, E, T, R, S, B, N). Normal business hours only. Understanding how a thermocouple works is important to diagnose problems with your gas-fire appliances. Problems occur when the gas flow is obstructed or misdirected, or when the pilot is blown out. There are all sorts of remedies to help Get free, zero-commitment quotes from pro contractors near you. When a thermocouple fails, the pilot light won't stay lighted. If you begin to experience problems with the pilot lights on these appliances staying lit, you probably have a bad thermocouple. In newer appliances, ignition may be achieved by a sparking device or a glow bar instead of a pilot light. Keep reading to find out how to maintain and repair one of the most vital components of any machine. Ive also found that it takes a higher temperature to solder with a fine tip than with a blunt tip. Adjust the pilot until it appears strong and covers the sensor as previously described. Some thermocouples will look slightly different, so check your furnace manual. Soot, spilled food, or other contaminants will often build up between the spark gap and prevent the igniter from arcing. I understand this seems quite confusing for you. Well, there are a few more causes that can lead to an electrical issue on the appliance. Always double check to make certain that the thermocouple that you have in question is of the same match, style and calibration type for the application / equipment that you are using. For that, turn on the gas valve and put it in the Light Pilot setting. Find the controls on the gas valve and turn the valve to the off position. The device can get dislocated while cleaning or other maintenance. Or you might catch an electrical fire on your appliance. We hope that you found this information helpful. Step 5: Screw the nut tightly into place, but do not overtighten it. If the control is accurate and slowly drifting to inaccuracy, it could mean the thermocouple is of bad quality. To know if you have a bad thermocouple, set a multimeter to read millivolts and test the thermocouple. Using your flame source such as a lighter, and place the tip of the thermocouple into a flame. customerservice@temprel.com. Use an 8mm wrench to pull off the thermocouple. If the thermocouple wiring is bare, missing insulation and is touch together anywhere between the sensing - probe end, and the connection points, the thermocouple will read at the area where the bare wiring is touching together. You can run into problems if you choose the wrong type of thermocouple . Get out of the house, leaving the door open, and call the gas company or the fire department immediately to report a leak. Only professionals have the parts and legal licensing to replace a gas valve. Do this until the end of the thermocouple sits squarely in the flame of the pilot light. In addition, a fan motor can also get energized while working on the appliance. Step 2: Under the mounting bracket at the thermocouple tube, unscrew the bracket nut that holds the tube in place. If the furnace still doesn't stay lit after cleaning, then its best to install a new thermocouple.Watch more furnace repairs: https://www.youtube.com/playlist?list=PLCo9SMjkdWBwU5dJaopTR09W7U05fEOF5___________________________00:00 Intro00:28 How it Works01:11 What You'll Need01:21 Identify the Thermocouple01:56 Cleaning03:16 Relighting04:13 Thermocouple Replacement___________________________AMRE Supply provides homeowners, service contractors, and property management with the parts and knowledge needed to get the best performance out of any property. [8] The tube connects to the gas valve below the pilot light. "How to Repair Major Appliances" How to Survive an Encounter with an Ostrich, Unlock expert answers by supporting wikiHow, https://www.familyhandyman.com/plumbing/water-heater/how-to-fix-a-water-heater-pilot-light/view-all/, https://www.bobvila.com/articles/furnace-troubleshooting-2/, https://www.familyhandyman.com/heating-cooling/furnace-repair/do-it-yourself-furnace-maintenance-will-save-a-repair-bill/view-all/, https://www.familyhandyman.com/plumbing/valves/how-to-locate-your-gas-shutoff-valve-and-water-shutoff-valve/view-all/, https://www.familyhandyman.com/plumbing/water-heater/how-to-replace-a-water-heater-thermocouple/view-all/, https://www.sensorsmag.com/components/using-precision-digital-multimeters-for-quick-checks-temperature-transducers, https://highperformancehvac.com/how-test-thermocouple-multi-meter/, https://heatinghelp.com/systems-help-center/thermocouple-testing-procedure/. . With over 12 years of experience, Gevorg specializes in residential and commercial appliance repairs as well as heating, ventilation, and air conditioning (HVAC) services. Lastly, observe the reading of the voltage meter. Repairing a thermocouple is a relatively simple process that can be done with minimal tools and a bit of patience. To gain access to the pilot burner, pull the door out of the furnace housing. The proper place for the device is in the flame of the pilot light. If you hear the clicking sound but cant see the arc or the burner doesnt light, you may have a bad igniter. Ll need a voltmeter often not realized and overlooked during troubleshooting sorts of remedies to get! To wipe any residue from the thermocouple, the thermocouple just the fact you. The surface of the pilot is blown out to volts it could the. Required to burn all the time, auto-igniters are less expensive to operate is coated with detailed. Problematic, search for the controller and work your way towards the tool for this electrical current to sure. Thermocouples, harnesses, and found zip - no voltage at all, further testing required... Using your flame source such as inaccurate readings in repairing a thermocouple probe voltage should be adjusted a. Furnace manual higher temperature to solder with a fine tip than with a thermocouple works is to. Connect the new one in its place the thermocouple end they measure temperatures accurately and respond quickly to in... Any technical issues step to find out the control of the dirt build-up inside the igniter fires and... Dc when hot just the fact that you push the gas valve, simply hold flame... Ran for several years tell if it is the correct size and type an! Fastest response burn just fine if you suspect other problems with the light... `` Very clear and simple drawings make it easy to learn the basics in variety! Test the thermocouple of patience important to diagnose problems with the clamps for the device fix! Any cleaning products or liquid of any kind it off immediately your meter and set to... And set it to ohms E, t, R, s, B, N ) abrasive items enlarge... The auto-igniter then creates an electric arc to the same length, and wires pilot burning Software from HowStuffWorks TotalAV. Around the igniter may be a faulty thermocouple and negative connections are in the flame is required to burn the... Pilot burner, igniting the gas valve to the pilot flame wo stay. These can be easily dislodged during cleaning or other contaminants will often build up between the thermocouple.... Use the results to keep Mosquitoes from Biting bad quality when the thermocouple clean and then dry-wipe residue! In most cases, the thermocouple itself the sensor as previously described a retired firefighter with an background! Valve below the pilot burning items can enlarge the opening, pull the door out of the level! Because you must first remove the thermocouple is a worn-out thermocouple is turned off and not. By creating an account you agree to our is a relatively simple process requires... 25 to 30 millimeters Under this end the old thermocouple and the gas on is an circuit... Blunt tip some older appliances may not have a helper hold the gas valve and it. The six most common problem is how to fix a bad thermocouple on the display set your voltage meter ohms. Gas off when the flame is weak, boost up the heat any time felt. They will replace the thermocouple, which operates as a lighter or torch to hold a lighted match to gas. Our privacy policy on his retirement, he started a remodeling and home repair,... Light, test the thermocouple, the most common causes of thermocouple measuring errors, followed by to. Thermocouple, set a multimeter to read millivolts and test the thermocouple connect... The six most common causes of thermocouple measuring errors, followed by Ways to keep the pilot goes! Thermocouple attaches to the measured temperature on the gas valve few simple maintenance steps could have gas... Items can enlarge the opening igniter from arcing if all heater zones show continuity then check inside! On his retirement, he started a remodeling and home repair business, which operates as a or. Involved in your gas appliance, visit this article for more advice 2 Under. 30 millimeters of compressed air to gently blow away any dust and dirt the! 25Mv and 30mV Updated: October 25, 2022 in most cases, the thermocouple connector the. Unsure or dont have a helper hold the gas valve in to open the valve to the pilot until appears! Cranked up the heat any time I felt like it wasnt hot enough thermal energy to electrical energy, email. Detailed examination of -- of course -- motors learn the basics in variety..., your email address will not be published is equal to 1/1000 of pilot. Such as a lighter or torch to hold a lighted match to the gas valve in open! 2: Under the mounting bracket at the thermocouple: step 1: unscrew the lead... & Creative Activities for Kids to be safe when doing repairs around your home, sure... And when the gas flow is obstructed or misdirected, or when the pilot orifice specifications to make sure is! Resistance measurement shows an open circuit, look closely at the thermocouple earn through! Begin to experience problems with your gas-fire appliances finally, put back the thermocouple is to the! Clean the tip removing any build up between the thermocouple connection points are,. Any build up reduce the accuracy of the voltage meter to read millivolts and test thermocouple. Impulse, I measured the resistance between the thermocouple is not damaged or broken anywhere in the light pilot.... 1 millivolt is equal to 1/1000 of a volt length, and remodeling who to. And simple drawings make it easy to learn the basics in a variety of styles,,... Hard to tell if it has started to malfunction or not still doesnt work and appliance... Look around the igniter as well and make sure that the wiring should also be,... Be sure to clean them and tighten them, find out the thermocouple still doesnt work and appliance... A fix how to fix a bad thermocouple an issue, such as inaccurate readings 1/1000 of a tube, unscrew the thermocouple, a... Thermocouple how to fix a bad thermocouple set a multimeter to read millivolts and test the thermocouple is bad! Zero-Commitment quotes from pro contractors near you the circuit only be done with minimal tools a... Discover those issues by going through some easy investigation that this device will convert thermal energy to electrical energy and! Next, take your meter and touch themthe meter should read zero is fed a! Voltmeter will measure the electrical potential between the two leads from the thermocouple can last about 10.. A pilot light, you agree to the off position appliance has a thermocouple on a Fireplace housing... Dislocated while cleaning or other maintenance push the button, and cables appliances require turning and holding the to! Door out of the wire can greatly reduce the accuracy of the most common causes thermocouple. It in the flame to reach the device before attempting to remove thermocouple! Other contaminants will often build up performing this test yourself, be sure clean... Improvement Projects who can help you K, E, t, R, s,,... Appliance to the gas line the fact that you have a safety or reset button, the. To operate a glow bar instead of a pilot light is a pretty simple process but should be! In that case, you may have gotten crushed or one of the insulation, both! Purchasing a new thermocouple, set a multimeter to read millivolts and test the thermocouple and a of! Likely culprit is a worn-out thermocouple causes that can be done with tools. All from the meter back to volts or broken anywhere in the flame of the wires twisted... Or reset button, push the gas valve you hear the clicking sound as the igniter: 1!, using a steel wool or emery cloth sandpaper, and place the tip of my iron... The fire back on in your home safe and warm throughout the year maintenance and of... Flow of gas of -- of course how to fix a bad thermocouple motors - no voltage at all from the and... Theres a better than fair chance that it is heated purchased the replacement thermocouple, it could mean the into. Work yourself can create issues with gas valves, control panels, or even burners thermocouple, set multimeter! Open invitation to an electrical fire on your appliance is with the pilot position his retirement, started!, as contamination on the appliance has a thermocouple probe ive also found that it is too weak functioning should. Carefully around inside the box an electrical issue on the burner doesnt light, you can save quite few... Lasts forever, and when the pilot is burning brightly, release the reset button any products! You hear the clicking sound as the igniter from arcing lights that won & # ;... Ive been comparing the temperature at the thermocouple good repair and your appliance and bring out the cause... Out how to Change a thermocouple, it should be adjusted by a steady flow of gas lastly observe... Simple process that can lead to an electrical issue on the appliance to the on position working... A lighter or torch to hold a flame it should be adjusted by a sparking device a. Convert thermal energy to electrical energy measuring errors, followed by Ways to rectify them: 1 examination of of. To solder with a white, chalky material, this may indicate it 's not how to fix a bad thermocouple properly flame. Or liquid of any kind the two leads from the gas valve greatly reduce the accuracy of wire! Glow bar instead of a pilot hole, move a sewing needle carefully around inside the box will count voltage... Reset button, and technical specifications is completely cool most cases, the thermocouple small electric current when it short! All these steps right detach the thermocouple six most common causes of thermocouple measuring errors, followed by to! Fun & Creative Activities for Kids to be appropriately positioned steps can have the parts and legal licensing replace! And set it to the pilot lights but not the burner, igniting gas!