Cooling fan permanently on

[Tone in't Fens]

I've owned my iMac for 10 months and I'm delighted with it; silent, fast, clean. I've only felt the need to lurk here before, now I'll be grateful for any advice.

Booted up this morning and the fan came on immediately and remains loudly on, before the machine even booted up. Any suggestions? The fan has hardly ever been on before.

 

[spinnerlys]

Intel-based Macs: Resetting the System Management Controller (SMC)

 

[Tone in't Fens]

Wow! That was easy!

Thanks Spinnerlys. (I did do a search first )