What to check, in order
- Set the steam release to Sealing
Sealing (Seal on newer models), not Venting, and pushed fully down on its post.
- Add thin liquid
At least 1 cup (250 mL) for a 3-quart pot, 1½ cups (375 mL) for a 6-quart, 2 cups (500 mL) for an 8-quart and 2½ cups (625 mL) for a 10-quart.
- Open and close the lid
The lid may not be in the right position for the programme.
- Check the sealing ring
It should sit snugly all the way round its rack, with no cuts or stretching. Instant says to replace it every 12 to 18 months, or sooner if it's stretched or damaged.
- Clean the float valve
Food on the float valve or its silicone cap can stop it rising. Take it out of the lid, clean it and check the cap is in good condition.
- Check the pot rim
Turn the inner pot upside down on a flat surface. The rim should be flush all the way round.
When to call an engineer
If none of this helps, the heating element may have failed. The Duo Plus manual lists that as a cause and says to contact Customer Care.
Parts people end up buying
Only if the checks above point to a part. Match it to your model number first: it's on a label on the back or the underside of the base.
- Sealing ringSearch on Amazon
- Float valve sealSearch on Amazon
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Checked against
- Instant Pot UK: Duo user manual (PDF)
- Instant Pot UK: Duo Plus with Whisper Quiet user manual (PDF)
- Instant Pot: frequently asked questions
Last reviewed September 2026. Manufacturers update their pages, and your manual is the final word.