The HE error code indicates a faulty heating element or heater relay.
Unplug the dishwasher and pull it out. Remove a metal panel on the dishwasher’s right side and check the heater relay.
It is advisable to put the washer on the back. Then remove the bottom panel.
In many Samsung dishwashers, heating elements and relays break down when home owners use instant water heaters (tankless water heaters). They require minimum gallon-per-minute water flow, and many dishwashers have even lower water flow rates. Therefore, a washer’s water heating systems are activated, but the device is not getting hot water at all. This happens every time you use your dishwasher, causing the heating element and heater relay to eventually fail.