Having a fan in your bathroom is essential. When you take a shower or just run hot water, steam is released in the air. You probably have seen how steamed up your bathroom mirror can be after a shower, especially when it is cold out. All that moisture in the air will go somewhere. If there isn’t enough ventilation, it could definitely cause mold and other water-related damage to your home. This is where the bathroom fan saves the day. It is important, though, that the fan is set up correctly for it to be effective.
The fan needs to vent the air outside of your home. If it just leads to your attic or some crawlspace, you will have problems there instead. The duct leading outside should be as short and straight as possible to avoid any blockage issues.
It is also good to inspect the fan and ductwork to make sure that it isn’t getting blocked by debris in the duct or that the fan is starting to deteriorate due to old age.