At start up, there is an overflow at the top of the side mounted plastic water inlet hsg. At first it is a spurt , then it receeds to a lesser continuous leak from the top of the hsg. This stops when the supply valve shuts off. We had a 'sandy' water incident a couple of days ago......coincidence?......is there a filter screen that can be cloged up and altering the flow. I restricted the flow but that didn't seem to affect anything?