Toilets fill with clean water after a few days of sitting
I have a 2014 XLR Thunderbolt with two toilets. After a week or two of sitting with all tanks empty, No water hooked up ,both toilets will fill and sometimes overflow with what looks like clear water. It appears that the toilet in the garage area will fill before the one in the bedroom. I was thinking it could be rain water maybe getting in the vent pipe. What doesn't make sense is the black tanks are empty but there is still clean water overflowing from the toilet. Any ideas what to check would be appreciated.
2014 XLR THUNDERBOLT