Things You'll Need:
- Ohmmeter
- Thermocouple welder
- Wire nuts
- Diagonal cutters
- Ohmmeter
- Needle nose pliers
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Step 1
Determine the problem with the thermocouple. Most likely, there’s a break in the wire or the thermocouple junction has separated. Use an ohmmeter to measure the resistance of the wires from each end to the junction. The resistance should be very low, less than a few ohms. Find the open wire in this way. If the junction has separated, it can usually be seen visually.
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Step 2
Strip a short length of insulation, enough to fit into a wire nut, from each end of the break in the wire if the problem is a broken wire. Insert the two ends into a wire nut and twist the wire nut clockwise to secure the two ends. The thermocouple should now function properly if there are no other breaks and the junction is not separated.
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Step 3
Cut the ends of the wire at the junction if the problem is a separated junction. It’s better to make a completely new junction if this is the case because it’s difficult to weld a junction together a second time.
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Step 4
Strip a half-inch of insulation from the ends of the wires where the junction has just been cut out. Twist the ends together with needle nose pliers. Be sure to make only one complete twist of the wires together so that the junction is not overly large.
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Step 5
Turn on the thermocouple welder. Insert the twisted wires into the welding spot and weld the thermocouple junction.
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Step 6
Turn off the thermocouple welder and test your thermocouple junction by measuring the resistance from the end of one of the wires to the end of the other wires. The resistance should be very low, less than a few ohms.
