This weekend I noticed a high pitched whine coming from the front of my fifth wheel when the furnace was running. The furnace is in the middle of the coach. Inspecting the propane bottles, I realized that the single regulator on the far side was vibrating slightly and the whine was coming from there - the switchover regulator on the door side of the coach seemed ok. Has anyone had a regulator go bad? When they go bad, do they whistle/hum/vibrate? I also had some trouble with the switchover regulator (pointer indicates which tank is active and gives a green or red indicator if there is, or is not gas available). I think this is because the far side regulator was not properly distributing gas. Any feedback would be appreciated.