Depending on the available space and location of the tanks they may have tied two vents together so there would be only one vent on the roof. If you have been on the roof where are the vent stacks?
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2009 Seville VF32KS
2019 GMC Sierra 3500HD Crew Cab Denali.
6.6 Diesel standard box.
Dagst1 reply is right on the money. My 23 footer has only one vent for both tanks. Your home has one sanitary sewer for all waste water and there is just one vent.
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Joe Munson
2024 Chevy 2500HD 4x4 6.6 Gas
2013 Zinger ZT23FB
Reese Weight Dist. w/friction sway control
Yes it is possible. If there is no "chase" they may connect them together. As long as it allows the black to vent out and both to vent in when you drain them it works.
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2009 Seville VF32KS
2019 GMC Sierra 3500HD Crew Cab Denali.
6.6 Diesel standard box.