OK - To me, this is really weird! We had some pretty hard rain last night, so this morning I went into our '83 Sovereign
to check for leaks. The only water I found on a cursory look was in the shower pan (and no, nobody has used the shower!). This is not the first time I've seen this - the last time I just thought I was going crazy and wrote the whole thing off.
Could rainwater from the roof vent fill the trap and backup into the shower pan? I highly doubt that as the shower drains OK into the greywater pan. There is no evidence of leaks or water anywhere else in the shower. Anybody else experienced something like this and have any tips before I start tearing things up to find the source of the rainwater leak?