Hi,
The [https://fccid.io/2AFOO-SP4218VGPBBT/User-Manual/User-Manual-3869932|user manual] states that an E1 error code indicates that the overheat protection device has been activated and to wait for 5-10 minutes so that the sensor resets and try again. If it still fails there's a problem with the sensor.
Unfortunately I cannot find any spare parts for the model online so you may have to contact the manufacturer's customer service about service or parts. See p.21 of the manual for contact details.