Replacing and calibrating the high-pressure sensor on an Instant Pot Duo can restore full pressure operation when the unit throws C6 errors or fails to maintain cooking pressure.
This guide covers diagnosis, part selection, disassembly, calibration, and safety considerations — formatted for technical DIY users.

🧭 1. Overview

Instant Pot Duo models (6 Qt, 8 Qt, Duo 60, Duo 80, Duo V2, etc.) use two separate internal sensors:

Sensor Function Typical Marking Location
High-Pressure Sensor Controls cooking pressure (≈ 10–12 psi). Sends feedback to control board. KSD105, KSD105A, YCD3005, YCD3008 Centered under inner pot, small disk with 2 wires
Thermal / Overheat Cutoff Shuts down at over-temperature (> 115 °C). KSD301 Off to the side of heater ring

If the cooker fails to pressurize, vents steam early, or displays C6L / C6H, the pressure sensor may be faulty or mis-calibrated.

🔧 2. Identifying the High-Pressure Sensor

Below is a labeled view of the Instant Pot Duo base (upside-down) with the bottom cover removed:

Instant Pot Duo High-Pressure Sensor

High-Pressure Sensor (KSD105) — small round metal puck mounted near the center with two insulated wires (often white or blue).

Thermal Safety Switch (KSD301) — slightly larger disk near the heater edge, heavier wiring.

You can use this image in your repo by placing the file
instant-pot-duo-pressure-sensor.png in your /assets/images/ folder.

🧰 3. Tools & Parts Required

Tools

  • Phillips & Torx (TT15) screwdrivers
  • Multimeter (for continuity)
  • Insulated gloves
  • Clean, non-metal surface for disassembly

Replacement Sensors

⚙️ 4. Replacement Procedure

  1. Unplug the unit and allow it to cool completely.
  2. Remove lid and inner pot. Turn cooker upside down.
  3. Remove bottom cover (Torx or Phillips screws).
  4. Disconnect wiring harness carefully from the control board.
  5. Identify the center sensor (high pressure).
  6. Unscrew and remove the old sensor; note its wire orientation.
  7. Mount and reconnect the new sensor.
  8. Reassemble the base and test with a “water test” (3 cups water, 5 min high pressure).

🔩 5. Calibration Adjustment

If the pot builds too little or too much pressure after replacement:

  1. Locate the small screw on top of the sensor (may have silicone or epoxy).
  2. Adjust in ¼-turn increments while unplugged:
    • Clockwise → decreases pressure (earlier cutoff).
    • Counterclockwise → increases pressure (later cutoff).
  3. Repeat the water test until pressure and timing feel correct.
  4. Once satisfied, seal the screw with a dab of heat-resistant silicone.

🧪 6. Verification & Safety

Perform at least two dry water tests before cooking food.

Test Result Action
Steam vents early Over-pressure; turn screw clockwise  
Float valve never rises Under-pressure; turn screw counter-clockwise  
Strong quick release, normal timer countdown ✅ Calibration good  

⚠️ Warning: Mis-calibrated sensors can lead to over-pressure and lid safety lock failure. Only small adjustments should be made.

📋 7. Maintenance Notes

  • Replace the silicone sealing ring yearly.
  • Check float valve and venting assembly for mineral buildup.
  • Log repair date and part number (recommended for service tracking).
  • Keep photos of wiring orientation for reference.

✅ 8. Summary

Step Task Notes
1 Confirm issue via C6 code or test Check sealing ring first
2 Identify high-pressure sensor Center disk with two wires
3 Replace sensor Use KSD105/KSD105A type
4 Calibrate screw ¼-turn increments
5 Verify with water test Steam behavior confirms fix

References:

File: 2025-11-07-Instant-Pot-Duo-Pressure-Sensor-Replacement.md
Image: assets/images/instant-pot-duo-pressure-sensor.png
Author: Preston Powell
License: CC BY-SA 4.0