what's the snowflake symbol for? it doesn't produce any heat

Diagnosis

The snowflake symbol on the De'Longhi TRD40615E thermostat dial represents the "Anti-Freeze" or "Frost Protection" mode. This is not a standard heating setting designed to warm a living space for human comfort; rather, it is a specialized maintenance mode designed to protect the internal oil components and the surrounding building infrastructure during extreme cold. When the dial is set to the snowflake position, the heating element will only engage if the ambient room temperature drops below approximately 5°C (41°F). The device monitors the air temperature via the internal bimetallic strip thermostat; if the temperature is already above 5°C, the heater will remain dormant, and you will notice no heat emanating from the fins. This explains why the unit appears to be "broken" or not producing heat when this setting is selected in a standard indoor environment. To confirm this is the cause, check if the power indicator light is on but the radiator remains cold to the touch; if so, the unit is simply waiting for the room to reach the freezing threshold before it triggers the heating cycle.

How to Fix It

To transition the unit from frost protection to active room heating, follow these precise steps:

1. Ensure the unit is plugged into a grounded wall outlet. Avoid using extension cords, as the TRD40615E draws significant current and may trip a breaker or overheat a thin cable.
2. Locate the thermostat control dial on the front panel of the device.
3. Grip the dial and rotate it clockwise, moving it past the snowflake symbol and into the numbered range (typically 1 through 6).
4. For immediate heat, rotate the dial to the maximum setting (6). This overrides the current room temperature sensor and forces the heating element to engage.
5. Wait 10 to 15 minutes. Because this is an oil-filled radiator, it relies on thermal convection; it takes significantly longer to warm up than a ceramic or fan heater.
6. Once the fins are hot, slowly rotate the dial counter-clockwise until the unit clicks off. Then, move it slightly back toward the right to set your desired maintenance temperature.

If That Didn't Work

• Check the Thermal Cut-Off Switch: If the unit was left on a high setting in a small space, the internal safety thermal cut-off may have tripped. Unplug the unit and let it cool for 30 minutes. Then, locate the reset button (usually a small red or black button on the top or rear) and press it firmly until you hear a click before restarting.
• Verify Power Supply: If the power indicator light is not illuminating at all, test the outlet with another device. If the outlet is live, check your home's circuit breaker or fuse box. The TRD40615E can occasionally trip GFCIs if there is a sudden surge during the initial heat-up phase.
• Inspect for Oil Leaks: Examine the base and the seams of the radiator fins for any oily residue. If the unit has leaked oil, the internal pressure drops, and the heating element may fail to transfer heat to the outer shell or trigger a safety shutdown. If oil is present, the unit is compromised and must be replaced.
• Test the Thermostat Sensitivity: If the unit clicks on and off every few seconds (short-cycling), the thermostat may be faulty. Try moving the unit away from curtains or walls to ensure the sensor is reading the actual room air and not trapped heat reflecting off a nearby surface.

Heads Up

• Avoid Covering: Never drape clothes or towels over the radiator fins to dry them. This obstructs airflow and can cause the unit to overheat, triggering the thermal safety switch or creating a fire hazard.
• Flat Surface Only: Always operate the TRD40615E on a level, hard floor. Using it on thick carpets can insulate the bottom of the unit, leading to overheating of the lower heating element.
• Dust Maintenance: Every few months, use a vacuum with a brush attachment to remove dust from between the fins. Dust buildup acts as an insulator and reduces the efficiency of the heat transfer to the room.
• Power Load: Do not plug other high-wattage appliances (like a kettle or toaster) into the same power strip as this radiator, as the combined load will likely exceed the amp rating of the strip.