Diagnosis
E1 means the temperature sensor is reading an error (likely an open circuit), and E2 means it's reading a short circuit. In plain terms, the machine thinks the sensor that tells it how hot it is isn't working right.
How to Fix It
First, try the hard reset: unplug, hold the power button for 15 seconds, wait a minute, plug back in. If the code clears, you're good. If E1/E2 returns, the sensor connection inside is probably loose or faulty.
If That Didn't Work
There's no safe user repair for a faulty sensor. You'll need to reach out to Cosori support with your error code. They're good about these known issues and will likely offer a replacement.
Heads Up
Avoid slamming the cooking pot into place, as that can jar the internal sensor connections over time.