Can the Lippert Siphon 360 Be Installed on a Sloped Roof?
Updated 05/28/2026 | Published 05/23/2026
Question:
My black water tank vent exits on a roof that is sloping towards the front of the trailer. Can this vent be installed on a sloped roof? The attached picture shows the slope at front of trailer.
asked by: Phil
Expert Reply:
Hi Phil,
The Lippert 360 Siphon RV Vent Cap part # LC389381 is intended to be a universal replacement for vent caps so it can or in multiple orientations. The Lippert aftermarket manual for the 360 Siphon, I've linked it below, says that the Siphon can be installed on sloped or angled roofs. This is because the vent can be mounted at an angle or even sideways as long as the base is secured tightly and correctly to the surface. We do also offer the Lippert 360 Siphon Vent Cap in black if you prefer, it's part number is part # LC389380.
Is your current black water tank vent not performing as well as you'd like?
Expert Reply:
Hi Phil,
The Lippert 360 Siphon RV Vent Cap part # LC389381 is intended to be a universal replacement for vent caps so it can or in multiple orientations. The Lippert aftermarket manual for the 360 Siphon, I've linked it below, says that the Siphon can be installed on sloped or angled roofs. This is because the vent can be mounted at an angle or even sideways as long as the base is secured tightly and correctly to the surface. We do also offer the Lippert 360 Siphon Vent Cap in black if you prefer, it's part number is part # LC389380.
Is your current black water tank vent not performing as well as you'd like?
Expert Reply:
Hi Phil,
The Lippert 360 Siphon RV Vent Cap part # LC389381 is intended to be a universal replacement for vent caps so it can or in multiple orientations. The Lippert aftermarket manual for the 360 Siphon, I've linked it below, says that the Siphon can be installed on sloped or angled roofs. This is because the vent can be mounted at an angle or even sideways as long as the base is secured tightly and correctly to the surface. We do also offer the Lippert 360 Siphon Vent Cap in black if you prefer, it's part number is part # LC389380.
Is your current black water tank vent not performing as well as you'd like?
Product Page this Question was Asked From
Lippert 360 Siphon RV Vent Cap for Black Water Holding Tanks - 4-1/2" Diameter - White
- RV Vents and Fans
- Vent Cap
- Plumbing Vent
- Roof Vent
- Plastic
- White
- Lippert
more information >
Phil
5/28/2026
Claire - Thanks for clarifying how the Lippert vent cap can be used. My existing vent cap is the standard issue one that most trailer manufacturers install. I sometimes have black tank smells so I was looking for a solution to improve on this.