This isn't a fuse caused problem. If the ignition system is electronic, it's most likely that the pilot light isn't lighting off. The spark is supposed to light the pilot flame. The presence of the pilot flame is then detected by the ignition module, which in turn start the combustion fan. After the air flow is detected by an air flow switch, then and only then, will the burner light off. I think the pilot orifice is plugged, allowing no gas for the spark to light. The pilot assembly needs to be removed and cleaned. When it's reinstalled, check to make sure the spark is about 1/2 inch long and light blue in color.
The pilot has to light off, before anything else can happen.
Post back to me, if you need further assistance.