Have a 2-year old Groco HF that I installed as a replacement (yes, your consistent advice about the Raritan as a better replacement is ringing in my ears!) in my ODay 302. It has performed well -- until yesterday. After winterizing, I used the head yesterday for the first time this spring and, while it pumps out the bowl on the dry flush setting, it won't work on the wet flush setting.I checked the vents -- no problem. Even tried it with the waste tank deck cap off.Those diagnostics came up zip.I wondered if I was getting water from the thru hull. So I checked the thru hull and when I backed off the hose clamp with the thru hull open, I got water around the clamp/hose -- so I assume I'm getting water thru the thru hull. But there just isn't enough suction to get it to the bowl. Do I need to prime this action? i.e. pull off the fresh water hose from the side of the pump, fill that with water and then see if it works? Surely I should get more than 2 years from the Groco? Or do I bite the bullet and get the Raritan? Thanks.