Take the line loose from the exit side of the LP regulator. Open the valve and see if the LP stops. do not do this longer than 20 or 30 seconds. Is the tank FULL? Tiffin had a problem with certain side mounted LP tanks a few years ago (do not think 2010 was in this) that the Pick up tube would pick up liquid. The ONLY fix was to replace the tank. This problem caused the LP regulators to freeze up and leak/fail. Also, the rubber line coming from the LP regulator, does it have a LOOP or a U---P-Trap? If so, you could have petroleum residue causing your problem. Doug