METHOD FOR DEALING WITH FAULT IN FUEL CELL SYSTEM

A fuel cell system includes a fuel cell stack, a first cooling line having first cooling water that passes via the fuel cell stack and circulates therein, a first radiator that cools the first cooling water, an air conditioning system that forms a heating loop with a first cooling line, a first cooling fan that blows exterior air to the first radiator, a first pump that pumps the first cooling water, a valve that switches a flow path of the first cooling water to the fuel cell stack or the first radiator, and a controller connected to the first cooling fan, the first pump, and the valve, and configured to detect a failure of the valve, control RPMs of the first pump and the first cooling fan to respective maximum levels, and control an RPM of a blower of the air conditioning system to a maximum level.