The E3 error occurs when the temperature of the water entering the machine exceeds 176F
Not unlikely, the water heater in your house is set at a high temperature mode (water temperature exceeding 120F). If it is, please, set it at a lower temperature. However, if the temperature of the inlet water is normal (not exceeding 176F), there is a problem with the temperature sensor, so take steps to replace it. If the replacement does not work either, you need to replace the main PBA.
Other Samsung dishwasher error code: