If you have video card software (like MSI Afterburner or EVGA Precision, or whatever the heck), then set the fans to 0%. As for case fans, if they're not plugged into the motherboard, they can't be adjusted. Otherwise you'd have to use the motherboard's software (or hope there's some fan controlling software that actually works). But in all honesty, I'd rather not go through that trouble, it's guaranteed unplugging the thing turns it off
As for warranty, sure, if you can convince them it's a defective product.