|You would expect warmth to be coming from any cooling fan. They are there to remove heat from some component. It's probably possible to replace just the fan if you can find an exact equivalent, but unless you have a problem I wouldn't worry about it.|
You might want to use a temperature monitoring program (e.g RealTemp) to monitor the temperatures inside your PC if you are worried about overheating. Also, make sure that any dust is blown out of heatsinks on CPU and GPU.