Can the Lippert Siphon 360 Be Installed on a Sloped Roof?
Updated 06/02/2026 | 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 install 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 >
Continue Researching
- Video: The Low-Down on the Lippert 360 Siphon RV Vent Cap for Black Water Holding Tanks
- Video: Replacement Dome for Dometic FanTastic RV Roof Vents: The Breakdown
- Shop: LaSalle Bristol XTRM Universal Self-Leveling Sealant - White - 10.1 oz - Qty 1
- Shop: Lippert 360 Siphon RV Vent Cap for Black Water Holding Tanks - 4-1/2" Diameter - White
- Shop: Replacement Dome for Dometic FanTastic RV Roof Vents - Tinted
- Search Results: trailer steps
- Search Results: travel trailer steps
- Search Results: camco rv vents and fans
- Shop: RhinoFLEX 90 Degree Elbow Fitting for Portable Wastewater Tank - Bayonet Style
- Shop: Global Link RV Lock with Bluetooth Connectivity
- Shop: Bauer NE RV Entry Door Lock for Trailers - Bluetooth - Right Handed
- Search Results: valcrum trailer bearings races seals caps
- Video: TorkLift GlowStep Revolution Scissor Steps Installation - 2015 Jayco Pinnacle Fifth Wheel
- Q&A: 4 Step Scissor Step for Camper Where Top Step is Close to Level with Bracket
- Q&A: TorkLift Glowstep Revolution Size Selection
- Q&A: Could the Cyclone RV Plumbing Vent # CAM40597 be Used to Ventilate a Camper Van
- Shop: MORryde Snap Trap P-Trap for RV Sewer Hoses
- Search Results: trailer hitch
- Video: Firestone Ride-Rite Air Bags with Easy Mount Compressor Feature Breakdown
- Shop: Trailer Hitch
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Article: Trailer Wiring Diagrams
- Search Results: trailer wiring
- Shop: Trailer Wiring
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Suspension Enhancement
- Video: How to Choose a Trailer Brake Controller
- Search Results: trailer tires and wheels
- Article: How to Measure for Trailer Hitch Drop


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.