I have the lid off of my 1000S at the moment to replace a failed HDD (4 & 1/2 years old so not a bad story, see below). If the 1100 layout is the same then there is not much on the right side of the board other than some hefty capacitors. Could be your HDD causing the noise and heat. If it’s within guarantee then contact Humax, if outside then take the lid off and check. To remove lid remove the rubber feet, then 4 screws beneath the feet and 1 at the back.
At the w/e my box repeatedly reported I needed to format the HDD, I reluctantly went down that route but at each attempt to format the box looped back to the fault message. Took out the HDD and mounted in a desktop cradle, Win 7 did not see any disk. Put an old desktop HDD in the box and it formatted and box performing OK. New AV drive on order.