To use a Masterbuilt 40-inch electric smoker, load it with wood chips and heat it for 30 to 45 minutes before placing food on the racks and setting a smoking time and temperature. Before its first use, season the smoker by running it for three hours at 275 degrees Fahrenheit with an empty water pan, adding 1 cup of wood chips in the last 45 minutes.
Fill the wood chip loader with 1/2 cup of chips, and place it into the loading slot. Turn the knob to Unload to drop the chips into their tray, but leave the loader in the smoker with the knob on Load during use. When adding food, use trays or place it directly on the racks, but leave space between each item for proper heating.
To use the control panel, push the On button and then the Set Temp button once. Increase or decrease the temperature with the plus and minus buttons. Set the timer by using the plus and minus buttons after pushing Set Time once for hours and twice for minutes.
For best results, do not cover the racks with aluminum foil or overload them with food. Control moisture by opening or closing the air damper. After each use, clean the smoker to prolong its life.