A 3-position switch has 3 settings: heat, fan only, and off. The fan option helps to cool the house on mild days. A pilot light indicates whether the heater’s power is on or off. A summer fan switch is a fan-only operation and allows the fan to run continuously and help cool the house. A heater upgrade upgrades your motor and blower to a designated HP. Options include 1/3 HP and ½ HP. A portability kit comes with casters and mounting bracket to make the air velocity unit heater portable. A heater control modifies existing components so that the heater accepts the control in the designated voltage and comes in 120 volt and 240 volt options. A power contactor is a relay for switching the electrical current on or off. A disconnect switch disconnects power to the heater, which makes it safer for electrical services to work on the heater. Many building codes require disconnect switches. Make sure your accessories and heaters fit together and that you purchase accessories compatible with your heater. Heaters can range from 30,000 BTU to 45,000 BTU to 60,000 BTU and can even go up to 125,000 BTU.