I have a 2015 challenger 37 kt, owned about 2 months. in that time I've dumped tanks about 4 times,first time di black, rear gray, mid gray, all went well, after that next dumps got nothing from mid gray even though kitch sink was used. opened said valve, inserted probe, all clear. seems sink water now going to rear tank. thinking maybe check/ overflow valve to divert to rear tank if mid gets full? can't seem to see one but nothing else makes sense. anyone have any info?
Ctpres's response confused me as I know my kitchen sink does drain to the mid-grey. So I got the drainage layout from thor and noticed revisions on the blue print:
6/16/15 redesigned kitchen sink plumbing
7/21/15 adjusted kitchen sink plumbing.
So it looks like 2016 and later models use the mid-grey for the sink and washer. Earlier do not.
Pros and cons to both options. I get more capacity than you. But I have to use a "Y" adapter and two sewer connections.
2018 Thor Challenger 37KT