P1 error appears when trying to start a pressure program; cooker does not build pressure.

Safety first: Ensure the cooker is cool and depressurized before inspecting pressure components.

• Clean pressure path: Remove and clean the steam release valve, anti-block shield, and any removable pressure channels in the lid. Blockages can cause abnormal sensor readings.
• Check sealing ring and float valve: Make sure the sealing ring is intact and the float valve moves freely. Leaks can prevent proper pressure buildup and confuse the sensor.
• Test with water only: Add 2–3 cups of water, close the lid, and start a short pressure program. If P1 appears before pressure builds, the sensor may be miscalibrated.
• Service calibration: Pressure sensor calibration requires service software or replacement of the sensor/board. Contact an authorized Oursson service center; do not attempt to adjust sensor values manually.