My thanks to Shark99 and Corpsie. I changed the heater inlet hose this AM as suggested by Shark99 and that took care of the noise. I cut open the old hose and looked at the restrictor. The part restricting the flow was only on one end of the restrictor and it appeared thin with some ragged edges. I needed to use a long needle nose with a 90 degree right angle on the end to release the hose.( next time it will be easier). Thanks again.