Universal Thermocouple Replacement Procedures

So what exactly is universal thermocouple? It is a safety instrument used for gas furnaces, water heaters, boilers, space heaters, and room heaters. Thermocouples should be replaced regularly as they are prone to corrosion. You will know that you need to replace it when you see a predominantly blue color in its pilot flame and when an ash appears on the thermocouple’s tip.

Good thing, thermocouple replacement – as well as universal thermocouple replacement – takes only a few minutes of your time so you can effortlessly do it on your own.


  • wrench
  • universal thermocouple
  • barbeque lighter or long match
  • screwdriver


  1. First , turn off the water heater’s gas supply. Do so by twisting its knob into the “Off” position. Wait at least ten minutes for the gas fumes to be fully-dispersed.
  2. Using a wrench, turn the nut on end of the thermocouple countercouckwise to disconnect the thermocouple from the bottom of the control box. The thermocouple is the smallest among the three tubes attached to the bottom of the control box.
  3. Pull the access panel off from the bottom of the water heater. If the access panel is attached with a screw or two, grab a screwdriver first to be able to unscrew and remove the access panel.
  4. Reach for the end of the thermocouple inside the water heater. Remember that it is held in place by a nut.
  5. Loosen the thermocouple by turning the nut counterclockwise using a wrench. Pull the thermocouple out of the water heater.
  6. Place the thermocouple replacement into the water heater’s interior and tighten the nut to hold the thermocouple in place with the use of a wrench.
  7. Turn the nut on a clockwise direction to attach the end of the thermocouple to the control box.
  8. 8.   On the top on the control box, you will see a knob. Turn it to the “Pilot” position.
  9. Using a barbeque lighter or a long match, light the pilot light beside the pilot gas tube and press and hold the reset button while the pilot light is lit. Turn the knob to “On” setting.
  10. Finally, attach the access panels back from where you removed it earlier. This completes your thermocouple replacement process.



  • With regards the thermocouple replacement cost, you’ll probably spend approximately $5 or so, which is much cheaper than replacing your water heater itself.
  • You should consider ordering thermocouple replacement parts online for more convenience. At Amazon, you can get them at a very low price with minimal shipping fees.
  • Before getting a thermocouple replacement, double-check your water heater to make sure that it is really defective.
  • Remove the defective thermocouple first before buying a thermocouple replacement in hardware stores. In this manner, you will be sure that it is the correct size that you need.
  • When choosing a thermocouple replacement, you should consider its type, insulation, and probe construction. With that being said, opt for a type K thermocouple. It is the most popular, flexible, inexpensive, and available in a wide variety of probes.