Don't be afraid to un-coil the tubing into a more straight line to ease installation of the device. Thread the end fitting of the thermocouple into the gas control valve and tighten it by hand. Step 5 Press down on the red button on the gas valve and light the pilot light while holding the button down. Watch out: Proper selection and installation of a thermocouple is important for the device to function safely, or for that matter to function at all., Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the. Remove the furnace's access cover. Using an open-end wrench, unscrew the nut that holds the thermocouple end fitting into the gas control valve. These things are really simple to replace. Watch out: Before trying a new thermocouple I'd suggest checking for debris in the pilot light orifice or tubing. Between the pilot supply pipe and the pilot burner, there's a brass tail/connector. If the furnace has been running, wait 30 minutes for the thermocouple to cool completely before continuing. The flame is blue and looks a nice size. Continue reading at GAS BURNER FLAME & NOISE DEFECTS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX. Unscrew the nut that holds the thermocouple end fitting into the gas … Like a thermocouple, the flame sensor has a metal probe and bracket, but it has no gas tube. Your problem now is that the pilot won’t stay alight without the thermocouple working, so your boiler now won’t fire. On 2020-03-28 - by (mod) - gas valve won't open: black wires at the thermocouple? Leave the pilot end of the thermocouple in place. G&S cooking ranges were identified as a subsidiary of MagicChef in 1969. The thermocouples used in building mechanical systems are generally type K: thermocouples used in heating boilers, calorifiers, geyers, gas burner applications (flame sensors). I have used canned air to clean and pushed and pulled everything. Building mechanical systems, oil & gas heating, water heaters, gas burner flame safety, water, mild chemicals, gases, dry areas, engines, hospitals & food industry. A problem arises when the thermocouple itself eventually “goes”. 1) Turn off the fire. Shop online through appliance parts dealers and compare their prices to those at local distributors. The system operates on a system that generally doesn't require an external electrical power source. Permalink. If the thermocouple is bad, the furnace usually refuses to ignite since the pilot light no longer burns. This switch is usually mounted on the furnace housing, but it may also be located on the wall near the furnace. Most gas furnaces use either a flame sensor or a thermocouple, sometimes referred to as a "thermal coupler." When it stops working, the furnace’s pilot light also turns off. Do I have to have that? On 2020-02-24 - by (mod) - thermocouple keeps failing too frequently. Honeywell, White Rodgers, and other manufacturers make universal replacement thermocouples, usually with a 30-millivolts (mV) rating for standing-pilot furnaces. Symptoms are I can light the pilot but it goes out as soon as I release the knob. Do not turn on nor try to use gas fired equipment if there is a gas leak. thermocouple was replaced on my air furnace - Bruce 11/17/12, Bruce, 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 When purchasing a replacement thermocouple or flame sensor, it's essential to make sure that it's compatible with your particular furnace model. I am GUESSING that they lead to a couple of spill switches that might be located on the draft hood of your heater or right near the burner opening.Those devices sense dangerous spillage of flue gases, are usually heat-activated, and some models require that the switch be manually-reset by pressing a reset button on the switch after it has cooled.See details at FLUE GAS SPILL SWITCH TRIPPING & RESET, Thank you for your answer of 5/2/19 to my on going problem. When heated the effect of the two dissimilar metals in contact with one another is the production of an electrical current. Replacing a Thermocouple or Thermopile if Cleaning Didn’t Work. ). You should find that you turn the screw counter-clockwise to tighten a right-hand-threaded connector. In general we think that thermocouples are less accurate and less sensitive temperature sensors than thermistors, but these low-cost and reliable temperature sensing devices have been used successfully in heating equipment such as gas fired furnaces, boilers, and water heaters for decades. Fire, Explosion, death and destruction of property can result. When the handle is perpendicular to the pipe, rather than parallel, the gas is off. All connections at the control box on a Patio heater take it out from where it ’ s pilot and... Supply and removing the old thermocouple end was un-screwed process controller or in a.. One thing '': a new Video Series where you turn the gas supply wwwdot new Member no with. Supply pipe and the pilot tubing is fastened to the off position this takes 30 for... Than gentle bending as described in the flame sensor is mounted right in the same position as the old and. Sage, Nov 20, 2007 # 1. wwwdot new Member and most are easy replace. 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