“E4” error code appears and the Gladiator freezer may not defrost properly, causing heavy frost on the evaporator and poor cooling.

Safety First: Unplug the freezer before working on the defrost system. The defrost heater operates at line voltage and can cause shock.

• Step 1 – Manually defrost: Remove food to a backup freezer or cooler. Leave the unit unplugged with the door open for several hours or overnight to melt ice. Use towels to catch water.
• Step 2 – Access defrost components: Remove the interior rear panel to expose the evaporator coil, defrost heater, and defrost thermostat/bi-metal.
• Step 3 – Test defrost heater: Disconnect heater leads and measure resistance with a multimeter. A typical heater will show continuity (tens of ohms). If open, replace the heater assembly.
• Step 4 – Test defrost thermostat: With the thermostat cold (surrounded by ice or in a cup of ice water), check for continuity. If open when cold, replace the thermostat.
• Step 5 – Inspect wiring and control: If heater and thermostat are good, the issue may be the electronic control board or its defrost relay. Replace the board if no power is sent to the heater during a forced defrost (per tech sheet procedure).