It might not have been the toilet. In our trailer the bathroom sink also drains into the black water tank NOT THE GREY as you would expect.
Just another possibility!
If you need to turn on your air conditioner,you've gone too far south!
2006 Safari SE 28W/LS,
2006 Silverado 2500HD/LT EC SB 4x4 Duramax/Allison,
Hensley Arrow , Honda EU2000i (propane),
160W Solar, 400W sinewave inverter,
3-stage smart charger, Xantrex battery monitor,
Sirius satelite radio