With sewer valve closed, connect the sewer hose with the open higher than the black tank or add a second sewer valve. Then add water and sewer treatment to black tank and let over night, then try opening and closing valve. This might take two or three days to dissolve the trash in the valve...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.