Thanks for the ideas. Part of the problem was that my old eyes couldn't distinguish what the blockage was in the narrow, deep spot where the screen was. I soaked and finally managed to pick out some black pieces of something. It seemed as though it was small shreds of black plastic. Some of the plumbing involved was black plastic - maybe it was shreds of threads. At any rate I put the part back and the water flow was much better. I still have to replace it since parts of it show wear. Dometic wants $79 for it on its site, the Dometic store on Amazon wants $35 for it, and many aftermarket versions are $10. (Gives you an idea of where Dometic makes some $$
![Blush](https://www.winnieowners.com/forums/images/smilies/blush.gif)
.) One aftermarket supplier claims to have upgraded the material to last longer ($20).
Just wanted to mention that there seems to be a consensus that this part is not robust. Many posts online mentioned they carried a spare with them on their travels. This part is poorly designed for easy cleaning. Also, the swirling action of the Dometic 310 seems poor compared to Thetford versions.