I have a 2000 coachman sports coach MB380. I need the sensors in the freshwater tank replaced. We are being told that the only access to the tank is to cut a hole through the kitchen floor. Can the tank not be accessed from under the coach? This is not logical that this would be the only access and have been told by another RV repairman that this should not be; however, we are in the middle of a repair and a maintenance insurance company at this point.