I have read several posts about the fan in the HWH bay ,but I have not seen any reference to the humming noise it creates. This is most noticeable in the morning when everything is basically "off" and no other competing noise. The fan runs a lot, but it also cycles on and off. As a matter of fact it will usually shut off just by opening the bay door and introducing more cool air. My question is how hot should the fan itself be? Mine is quite warm to the touch and I wonder if this is the early signs of bearing failure and the cause of the hum.