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. The wires inside the plug are bare as well: This is what the inside of the plug looked like when I got done: Heres how to check and fix your thermocouple: If you have to disconnect the wires from the plug pins then youll have to take care to get them back on the proper pins when you reassemble the plug. 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. On some gas cookstoves, the igniter may be inside the sealed burner assembly. 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. 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. Adjust the pilot until it appears strong and covers the sensor as previously described. Gently rub the toothbrush over and around the igniter head. Sometimes you don't need to spend a single buck, and a little cleaning will do the trick for you. Thermocouples are designed to detect a pilot light's loss of heat and close the gas valve to prevent a gas leak. Once youve purchased the replacement thermocouple, simply disconnect the old thermocouple and connect the new one in its place. We hope that you found this information helpful. Now, remove the valve using pliers. This instrument contains two probes; red and black. Remove the valve using your pliers. It should have a yellow tip and cover the tip of the thermocouple. 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. 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. Step 2: Hold a lighted match to the pilot orifice and turn the gas valve to the ON position. You can run into problems if you choose the wrong type of thermocouple . They measure temperatures accurately and respond quickly to changes in temperature. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); How to Fix a Thermocouple on a Water Heater? A thermocouple lasts for an average of 10 years, and you need to replace yours if there is too much rust on it. Contact an appliance repair service to check the igniters. To replace a thermocouple: Step 1: Unscrew the copper lead and the connection nut inside the threaded connection to the gas line. How to know if a thermocouple is bad? The gas control thermostat will be on the outside of the gas tank, possibly on a nearby wall. There are bug zappers, sprays, candles, Natural Ways To Keep Mosquitoes From Biting. Its because of the dirt build-up inside the igniter. 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. Most appliances hold the thermocouples in place with a spring clamp. The impact may be minimal, or it can mean hundreds of thousands of dollars in lost product or delayed production. Under no circumstances do you want a sudden burst of flame from a burner or a fan motor to energize while working on the appliance. Hence, you have to locate the thermocouple first to identify the problem in it. The thermocouple will sit so that the tip of the thermocouple is directly in the pilot lights flame. If you buy through links on our site, we may earn a commission. With over 12 years of experience, Gevorg specializes in residential and commercial appliance repairs as well as heating, ventilation, and air conditioning (HVAC) services. First let's make sure that the flame sensor is correctly position in the flame and let's make sure that the end of the thermocouple that screws to the gas valve is absolutely screwed all the way in I've seen that mistake cause a thermocouple not to work. Then again, a way too strong flame is also inaccurate. Your email address will not be published. The igniter is usually immediately adjacent to or at the edge of the burner. By creating an account you agree to the Hunker, How to Change a Thermocouple on a Fireplace. Your voltage meter has two probes, one red and one black. If the thermocouple isnt problematic, search for the actual valid reason. If you begin to experience problems with the pilot lights on these appliances staying lit, you probably have a bad thermocouple. Turn off the fireplace gas valve and remove the front panel from the fireplace. As a small thank you, wed like to offer you a $30 gift card (valid at GoNift.com). . Thank you.". Dennis is a retired firefighter with an extensive background in construction, home improvement, and remodeling. This guide reviews how to replace a thermocouple to ensure gas appliances stay in good working order, as well as how to relight a pilot light. Hunker may earn compensation through affiliate links in this story. To examine the gear, youll need a voltmeter. You may have to wiggle it a bit before it comes loose. Ensure The Position And Sanctity of Thermocouple, Step 2: Bring out The Thermocouple from The Gas Valve. If youve got a few minutes to spare, stay with me! 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. It may have gotten crushed or one of the wires may have broken off. While buying the voltmeter, try to get one with the clamps. The thermocouple is made up of a tube, a bracket, and wires. The thermocouple has two dissimilar metals that form an electrical circuit. Sometimes the sporadic movement of the thermocouple can also shake its position. If you suspect this is the problem instead of the thermocouple, call a professional. I know this is the first question that hits your mind. Lastly, observe the reading of the voltage meter. Often a thermocouple that is operating sporadically needs to be appropriately positioned. The thermocouple doesnt have wires. For that, turn on the gas valve and put it in the Light Pilot setting. Be sure to turn off the power to the device before attempting to remove the thermocouple. The thermocouple doesnt have wires. 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. Yes, you can clean a thermocouple, but the task must be done with a light touch. Use a can of compressed air to gently blow away any dust and dirt from the thermocouple. Since no flame is required to burn all the time, auto-igniters are less expensive to operate. Take off the valve housing aside through a 133mm socket wrench. link to Does Citronella Actually Help Keep Bugs Away? Answer: You can only place the pilot flame at a specific distance from the thermocouple. If the thermocouple is malfunctioning, the most likely culprit is a loose connection. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings. Using a small pair of needle-nose pliers is a safe way to adjust the thermocouple clamp. Here are a few ways to pinpoint a faulty thermocouple as the culprit. Learn about the Maintenance and Handling of Thermocouples, Email: 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. You should also turn the appliance off before working around the pilot light and burner. 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. Your furnace pilot light should burn just fine if you have got all these steps right. In newer appliances, ignition may be achieved by a sparking device or a glow bar instead of a pilot light. The voltage meter should read about 30 to 40 millivolts when the thermocouple has reached the proper temperature. Auto-igniters are quite simple. When it stops working, the furnaces pilot light also turns off. 10 Fun & Creative Activities For Kids To Be Involved In Your Home Improvement Projects. Sounds interesting? I disconnected the wires from the plug pins, cleaned more fuzz out of the way, and untwisted the wires. Remember to be safe when doing repairs around your home. Your furnaces thermocouple is usually located right in the flame of the furnaces pilot light. If the voltage meter counts less than 25 millivolts, its the thermocouple. Locate the thermocouple on the gas control thermostat. Step 2: Under the mounting bracket at the thermocouple tube, unscrew the bracket nut that holds the tube in place. Most of the gears set the thermocouple with a spring lamp. I understand this seems quite confusing for you. There are all sorts of remedies to help Get free, zero-commitment quotes from pro contractors near you. For example; a J type calibration thermocouple cannot be used on a specific application calling for a K type thermocouple. In any case, Ive been comparing the temperature at the tip of my new iron to the measured temperature on the display. Sounds exciting right? Your appliance may not have a pilot light or a thermocouple. It will secure your own safety. 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. Or you might catch an electrical fire on your appliance. Your igniter may or may not have a pilot hole. What does a thermocouple look like and how do you find it? B) Remove and clean the pilot burner, pilot orifice, and tube. Do You Need Emergency Furnace Repair? Theres about three ohms of resistance across the thermocouple at that end. Pull the valve housing aside using your 13mm socket wrench. Normal business hours only. If the thermocouple isnt bad, then whats creating a problem? Do You Need to Hire an Electrician? If the thermocouple doesn't function after cleaning it, it would be best to replace it with a new one. You should be done in under 20 minutes. Support wikiHow by Once I got all the fuzz from the cloth covered wires out of the way, I could see that the bare wires inside had been twisted around and shorted out. If so, unscrew them from the pins and untwist the wires. Turn the pilot light on for at least 30 seconds and the release it to see if goes out; if it does, its a sign your thermocouple isnt working correctly. (J, K, E, T, R, S, B, N). The cheap ones have the thermocouple sticking out of the end of a cloth covered cable. Before the test, turn off the gas supply because you must first remove the thermocouple. Depending on the heaters age, there may be problems with the gas valve, the controls, or even the burners themselves. The thermocouple on your appliance is with the pilot light. If the resistance measurement shows a dead short from pin to pin, check the thermocouple itself first. By using this Site, you accept and agree that following any information or recommendations provided therein and all channels of digital content is at your own risk. A few simple maintenance steps could have your igniter up and running again quickly. Newer gas appliances have igniters that start the pilot light as needed. Use it to try out great new products and services nationwide without paying full pricewine, food delivery, clothing and more. Must present coupon at time of service. Now that is working again, it shows about 15 ohms. Remove the thermocouple by unscrewing the copper lead and connection nut (first) and then the bracket nuts. It might help to put a piece of heat shrink tubing over one of the wires before reassembling it. Wipe away any remaining dirt or soot on the thermocouple with a clean, dry cloth. This is what a cheap K-type thermocouple looks like: Note that the wires to the thermocouple (the little metal ball at the end of the cable there in the upper left corner of the picture) are bare - they can easily be shorted by bending or twisting the wires. So that it can produce an ample amount of electrical flow. 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. 2. Some panels have a screw on each side that needs to be removed and other panels lower on a hinge. Connection from the thermocouple to the valve. Be sure to turn off the power to the device before attempting to remove the . If the connections appear loose or corroded, then you will need to clean them and tighten them. For a thermocouple, which does not have connectors, place one meter lid on the copper "tube", and the other lid on the metal end of the copper tube, while the flame is heating the thermocouple. 30 July 2020. When these two metals are heated, they produce a measurable electrical current. Absolutely you dont want that. Turn the gas back on and try the appliance. Answer: Definitely, you can! If youre uncomfortable performing this test yourself, be sure to call a licensed HVAC contractor who can help you. After that, generate heat on the thermocouple. The first step in repairing a thermocouple is to identify the problem. Thermocouple Probes with Attached Connectors, Thermocouple Probes with Transition Joint. We use cookies to make wikiHow great. Thanks to all authors for creating a page that has been read 100,018 times. You can test this yourself using a multimeter, but you may need a helper to keep the pilot flame burning while you do it. Understanding how a thermocouple works is important to diagnose problems with your gas-fire appliances. An exposed junction thermocouple offers the fastest response. 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 i. 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. Reading the voltage level is the last step to find out the real cause. On his retirement, he started a remodeling and home repair business, which he ran for several years. Step 1. Step 4: Under the bracket, screw the bracket nut over the tube. 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. Therefore, inspecting and testing your thermocouple should be part of your furnace maintenance. In furnaces and water heaters, and in some ranges and dryers, the pilot light is accompanied by a safety device called a thermocouple -- a heat sensor that turns the gas off if the pilot flame is extinguished. No wonder that it is also used in the water heater. Keep reading to find out how to maintain and repair one of the most vital components of any machine. Just using the probe had twisted the wires around inside the strain relief and shorted them. Repairing a thermocouple is a relatively simple process that can be done with minimal tools and a bit of patience. Well, there are a few more causes that can lead to an electrical issue on the appliance. Water Heater Maintenance: Extend Water Heater Life Step 2 Burner assembly Remove the burner assembly and detach the thermocouple. It should be low, but definitely not a dead short. It consists of a heat sensor connected to a solenoid; when the sensor is not heated by the pilot flame, the solenoid closes the gas supply line. 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