[dbruce222@gmail.com]

I had a similar issue on my 4000. First it was a failing pump in my shower sump. It would work intermittently but not at full strength. That fixed it briefly then it came back. Ended up discovering a cracked check valve just outside the same shower sump. I think I’ve finally got it squared away, but that gives you a couple things to check.

I have a 4000 that just purchased. have the same problem. Where is the check valve. The shower sump seems to be workeng.

Dave