I live in a one-level condo with a closet that holds both the gas furnace and water heater. 2 things. 1. When the gas furnace turns on, it sounds like the 4-horseman coming from the heavens for armageddon. It is the fan! What do I have to do quiet that fan? Would WD-40 sprayed into the fan(s) do anything? 2. The water heater turns on and off every 5 seconds or so. On..5 seconds...off 5 seconds ...etc...etc. If these two things are normal ..how do I sound proof that closet?? Any suggestions would be appreciated.