how to fix a bad thermocouple

If the thermocouple is out of alignment, gently pull or push the spring clamp. Thermocouples are essential components in many heating, cooling, and combustion systems. Use the chart below to make sure that the positive and negative connections are in the proper order. The cheap ones have the thermocouple sticking out of the end of a cloth covered cable. By using our site, you agree to our. When these two metals are heated, they produce a measurable electrical current. Or you might catch an electrical fire on your appliance. Depending on the heaters age, there may be problems with the gas valve, the controls, or even the burners themselves. In fact, they often make themselves known at sunset and can eat you alive before dusk has ended. I understand this seems quite confusing for you. Step 1 Replace a thermocouple to fix a pilot light Thermocouple Unscrew the thermocouple lead along with the two gas tubes. *Note: If you are inexperienced, wed recommend calling a licensed heating contractor to perform the test! Use any type of steel wool or emery cloth to wipe off any dirt. Locate the thermocouple on the gas control thermostat. After that, generate heat on the thermocouple. 2 The thermocouple is made up of a tube, a bracket, and wires. To bypass the thermocouple: Move the tilts switch wire aside. You can eliminate this possibility if there's enough room for you to reach in your hand and reposition the probe closer to the flame. If the reading is less than 25 millimeters, it should be replaced. Although thermocouples are reliable, temperature measurement errors can occur for various reasons. Better to be safe than sorry. Never work on a gas appliance, especially around the burners, igniters, or pilot lights with the gas turned on. 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. So, I have prepared a broad discussion to find out the actual reason. Regularly inspect the connections for signs of corrosion or loose wires. If you cannot see or detect problems proceedwith the test. 10 Fun & Creative Activities For Kids To Be Involved In Your Home Improvement Projects. Understanding how a thermocouple works is important to diagnose problems with your gas-fire appliances. It might help to put a piece of heat shrink tubing over one of the wires before reassembling it. 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. Mosquitoes have a way of ruining an otherwise perfect evening. Set your voltage meter to read voltage (V) in millivolts. The plug fit better and held tighter, but still no temperature. Your email address will not be published. Most problems with this type of valve are due to thermocouple problems. Compatible Thermocouple Calibration Type? Unhook Everything From the Gas Valve 03. The device can get dislocated while cleaning or other maintenance. Expert Interview. unlocking this expert answer. Remove the thermocouple by unscrewing the copper lead and connection nut (first) and then the bracket nuts. A burned out or broken thermocouple should be replaced. Install The New Thermocouple 06. Maybe itll help, maybe it wont. You can check a thermocouple with a standard volt meter set to the Ohm's / Continuity function by checking across the positive and negative leads, in order to determine if the probe circuit is open or not. The pilot should heat the top 7/8" of the thermocouple with a clean (blue) flame. Your Promotional Selection Has Been Applied! He worked in the trades part-time while serving as an active firefighter. The welded end of the thermocouple probe should protrude at least 1.5 inches (0.0381 meters) into the kiln chamber. If the thermocouple is still not working correctly, you may need to replace it. Be sure to inspect before you test, however, to ensure that there are no obvious problems that could affect the readings from testing! Most of the gears set the thermocouple with a spring lamp. An orange color from Iron Oxide on J and K types indicates internal moisture leakage. Since no flame is required to burn all the time, auto-igniters are less expensive to operate. Gevorg Grigorian. Now that is working again, it shows about 15 ohms. Start at the cable connector for the controller and work your way towards the tool. FIND LOCAL CONTRACTORS. Before jumping to the conclusion that the thermocouple is at fault, look at the pilot flame. Call Air Experts at919-480-2727or contact us online today to schedule furnace repair service! But cleaning the device wont fix any technical issues. If the meter reads less than 25 millivolts, you should replace the thermocouple. Take off the valve housing aside through a 133mm socket wrench. Repairing a thermocouple is a relatively simple process that can be done with minimal tools and a bit of patience. Sometimes the sporadic movement of the thermocouple can also shake its position. Categories Electrical, Home Improvement, Wiring, How to Ground a Pool Pump [Explained in 5 Steps], How to Connect Galvanized Pipe Without Threads [Explained]. Ive been using the K-type thermocouple with my multimeter to measure the temperatures. To do this, youll need a voltmeter with a thermocouple probe. The pilot light is a small open flame that is fed by a steady flow of gas. Step 3: Insert a new thermocouple into the hole in the bracket, steel tube facing up and copper lead down. Make sure that the wiring is protected with insulation and is not damaged or broken anywhere in the circuit. Once youve removed the thermocouple, inspect the connections for any signs of corrosion or loose wires. Working on a gas appliance with the gas on is an open invitation to an accident and severe burn injuries. Do You Need Emergency Furnace Repair? , it must be hot. Special Offer on Antivirus Software From HowStuffWorks and TotalAV Security. Present coupon at time of service. The Red wire is generally the negative (-) wire in thermocouples, harnesses, and cables. This instrument contains two probes; red and black. Clean the threads of the connecting nut with a pencil eraser and re-tighten. If you begin to experience problems with the pilot lights on these appliances staying lit, you probably have a bad thermocouple. Working with response times. The thermocouple will sit so that the tip of the thermocouple is directly in the pilot lights flame. 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. A thermocouple is a safety device that helps control the gas supply in gas-heated furnaces. After that, generate heat on the thermocouple. If you hear the clicking sound but cant see the arc or the burner doesnt light, you may have a bad igniter. Set the multimeter to read millivolts, then start the pilot and have your helper hold in the gas control knob to keep it burning. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/0\/04\/Test-a-Thermocouple-Step-1.jpg\/v4-460px-Test-a-Thermocouple-Step-1.jpg","bigUrl":"\/images\/thumb\/0\/04\/Test-a-Thermocouple-Step-1.jpg\/aid9649384-v4-728px-Test-a-Thermocouple-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"