I've got a 2014 Voltage 3605. My driver side propane has the switch over valve and the curb side has the single regulator. Right now my driver side is empty and the system is switched to the curb side bottle. When the furnace fires up and it fires up fine the bottle "sings". It woke me up the other night with a rendition of "moon over mymommy" . It works fine, fires up, cycles off, fires up no problem. It just makes noise. Thoughts?