Proper voltage plays a pivotal role in the function of your Suburban furnace. When the voltage in your RV drops too low, the blower wheel will not spin to the proper speed to activate the low air flow switch or sail switch. The low air flow switch is what tells the gas valve to open to create heat. If your voltage is too low, you will get no function out of your furnace. If it is malfunctioning make sure to check your voltage first!