maple1
Minister of Fire
Mike,
If you have that howling, thats usually not a good thing. You have others here who know waaaaay more than I do on this (Ill be posting my own "help me!" thread before too long), but the 007 seems like a lot of pump for that short run. There should be very little head loss just to move around that little loop.
Wonder also if extra noise could be a sign of pumps & flows working against each other?