Safety first: Disconnect power and wait for the unit to cool. Use insulated tools and avoid touching live circuits.

Basic verification:

Confirm the unit powers on and the fan runs, but there is no heat and E4 appears. If the unit is completely dead, see power-related faults instead.

Heater circuit inspection:

Remove the cover to access the heating element assembly. Look for broken coils, burn marks, or disconnected spade terminals.
Check that all heater terminals are firmly attached and not oxidized or loose.
With a multimeter, test continuity across the heating element. A reading of OL (open) indicates a failed element.
Locate any high-limit thermostat or thermal protector in series with the heater and test for continuity. An open device will prevent heating.

Control board check:

Inspect the main control PCB for a burnt heater relay or charred traces in the heater circuit area.

Corrective action:

Replace a failed heating element with a Samsung-specified replacement for your model.
Replace an open high-limit thermostat only after confirming there is no airflow blockage or other overheating cause.
If the heater and thermostats test good but the relay is burnt or not switching, replace the main control PCB.

Air fryer will not heat and shows E4 on the display shortly after starting.

Possible Causes