If your Instant Pot Duo Evo or Instant Pot Pro does not pressurise and makes a continuous hissing noise, the steam outlet valve (steam button) is faulty. You can check this yourself.
Remove the steam button from the lid and invert it.
You will see one of the situations below:
Top photo: the seal is missing and the steam knob is defective. We can supply a new one.
Bottom photo: you can see a silicone seal element. the steam knob is fine.
