Gasoline fumes in a bilge or engine compartment, with or without a blower fan, have the potential to be a serious risk at any time. Firstly, because fuel leaks create new fumes as rapidly as the blower clears old fumes away. With the fan off, the hazard is increased. Secondly, the blower fan is typically not operating prior to engine start-up, thus offering no protection from the ignition of fumes be electrical short circuit, battery hydrogen explosion, smoking or their causes. Fireboy-Xintex offers a full line of gas detectors and accessories to match your specific needs.