Replacing & Upgrading Thermocouples

REV: 2/1/2025

Introduction: What Is a Thermocouple?

A thermocouple (TC) is a temperature sensor inside your kiln that relays heat readings to a controller or pyrometer. It consists of two dissimilar metals which generate a tiny voltage that changes with temperature.

• Type K (Chromel/Alumel): Less expensive but gradually degrades over time, requiring replacement. 
• Type S (Platinum/Platinum-Rhodium): This is a premium upgrade, but it won't degrade over time.

See this page for more details on how they work

Polarity & Lead Wires

Correct polarity is essential—mixing up positive (+) and negative (−) leads can cause false readings. See this page for more information.

• Type K (Yellow Sheath): Yellow = positive (+), Red = negative (−).
• Type S (Green Sheath): Black = positive (+), Red = negative (−).
  • European Type S TCs sometimes reverse the red and black leads. Just ensure the correct polarity at the controller. If reversed, your controller may show negative temperatures or error codes, but it won’t harm anything—swap the leads.

Checking Type K Thermocouple Tip

Type K thermocouples degrade over time and should be visually inspected. 

• If your kiln uses open-ended protection tubes, you can inspect the thermocouple from inside the kiln chamber. 
• If your kiln uses the older closed protection tubes, you must remove the thermocouple to inspect it.
  1. Disconnect Power – Unplug the kiln or switch off the breaker.
  2. Open Panels – Remove the control panel screws, open it, then unscrew and swing open the element box.
  3. Remove Thermocouples – Unscrew and pull out the thermocouple to inspect the tip for severe corrosion.

Replacing a Thermocouple

1. Disconnect Power – Unplug the kiln or switch off the breaker (lock out if in a school, commercial, or industrial environment).
2. Open Panels – Remove the control panel screws, open it, then unscrew and swing open the element box.
3. Detach Wires – Disconnect thermocouple wires (take photos for reference).
4. Remove Old Thermocouples – Unscrew and pull them out; clip/strip wire ends if oxidized.
5. Install New Thermocouples – Secure with screws/spacers and reconnect wires.
6. Close Everything Up – Reattach the element box, wire terminals, and outer panel.

What is the placement of thermocouples on a 2 or 3 zone kiln?

See this page

Upgrading: From Type K to Type S

1. Remove Old Thermocouple – Disconnect wires and unscrew the Type K thermocouple/tube.
2. Fill Hole – Plug the larger hole with a firebrick plug and brick cement; let dry.
3. Drill New Hole – Use a 5/16" bit for the Type S thermocouple; insert the new thermocouple.
4. Secure Thermocouple – Drill a small pilot hole if needed, then attach with screw and washers.
5. Use Correct Wires – Type S wire set: black (positive), red (negative).
6. Controller Configuration – Set your kiln controller to Type S settings.
7. See this page if upgrading on a DynaTrol
8. See this page if upgrading on a Genesis

Controller Configuration

WARNING: Ensure the jumper is correctly positioned for your thermocouple type (Type K or Type S). The wrong setting can cause severe overfiring and meltdown. Place the jumper on one prong for Type K, or both prongs for Type S. See this for more information.

DynaTrol

1. Press Other
2. Input the code 443 and press Enter
3. Press Other to cycle through the options until you reach TYPE
4. Press Enter
5. Press any number key to cycle between K-TH and S-TH
6. Press Enter

Genesis

1. Press Menu
2. Select 7 - Factory Config
3. Enter the code 443 and press Save
4. Select 1 - TC Type
5. Select the desired Thermocouple type
6. Press Save