There have been a few posts about the fan running at high speed after the 360 update, the fix is to have the box replaced, you just need to convince someone how loud the box is, some users have been asked to post a video 😕
You need to call Virgin on 150 to report a fault or wait here for one of the forum team to pick this up which might be 2 to 3 day's.
When phoning choose the option to report a fault, then ignore all the options offered and hopefully you should then be placed into a queue to speak to someone.