out of control fan

I purchased the 21.5 in imac last november. I noticed that the fan seemed to be running a lot, and while it was kind of annoying, this is my first mac so I thought maybe thats just how they are. However, my parents just bought the 27 in imac in april and i've noticed that their fan seems to almost never be running, while mine is almost constant, unless its asleep. Is this just because of the difference between the sizes or is there something wrong with mine?? Now that i've seen how quiet theirs can be, mine is starting to really annoy me haha.

Any help or advice would be appreciated.

Thanks.

Welcome to the Mac Forums. The fan in your iMac 21.5" machine should not be running constantly. Since the machine is still under warranty, I suggest you make an appointment with your local Apple store genius bar and take it on in for them to look at.

Anything that involves fans usually has something to do with the iMac's SCM. I suggest you try resetting the SMC.