Originally Posted by SC2150
Make sure your drain valve is closed....if accidently left open, the valve will rattle loud.
at idle, feel the end of the drain hose....should be NO suction.
I'm fairly certain it's closed. Closed being the screw valve is all the way out or extended. Reverse threading like a radiator. Nonetheless I'll check the vacuum. Interestingly it didn't make noise today.