RV Sewer Hose and Fittings: A Practical Guide

Guide · Updated 2026-11-09 · General guidance; rules vary by state, park, and operator, so follow posted signs.

Short version: most RVs need a 3-inch hose with a bayonet fitting at the RV end. Carry about 20 feet total (often a main hose plus an extension), a clear elbow with a 4-in-1 adapter for the inlet end, and caps. Choose a thicker-walled hose that resists punctures. Store it rinsed, capped, and away from your drinking-water gear.

Your sewer hose is the one piece of RV gear that only gets noticed when it fails, usually at the worst possible moment. Getting the right setup is cheap insurance. This guide covers what matters when you choose one, what each fitting does, and how to keep the whole kit lasting.

Diameter and the RV end: 3-inch bayonet

The great majority of RVs have a 3-inch sewer outlet with a bayonet fitting: a ring with lugs (small posts) that a hose fitting slides onto and twists to lock. A rubber gasket inside the hose fitting makes the seal. Because it’s nearly universal, most RV sewer hoses are 3 inches in diameter with a bayonet fitting on one end.

A few rigs have something different. Some have a separate, smaller gray outlet, a cassette toilet, or a macerator system that pumps through a smaller hose. Look at your outlet before you buy anything.

Check the gasket inside the bayonet fitting each time. A missing, twisted, or cracked gasket is the most common cause of a leak at the RV end. Spare gaskets are inexpensive. Keep one in the bin.

Length: how much hose do you need?

Dump station inlets and campsite sewer connections are not always where your outlet ends up. Sometimes it’s a few feet. Sometimes the site was designed for a shorter rig and the sewer is 15 feet away. Many RVers carry about 20 feet total, and often split it as a main hose plus a 10-foot extension. A RhinoFLEX 10 ft sewer hose extension is one example of an add-on section.

Why not just one 20-foot hose? A single long hose is heavier, harder to drain completely, and harder to store. Shorter connected sections let you use only what you need. That said, every joint is a potential leak, so don’t chain more sections than you need.

Wall thickness and durability

Sewer hoses are thin, flexible, and get dragged across pavement, gravel, and sharp edges. The cheapest ones are often very thin and can puncture or split. When you compare hoses, look for:

Thicker walls. Many manufacturers list wall thickness in mils. A thicker wall resists pinholes and abrasion better.
Reinforcement. A steel or polymer wire helix keeps the hose round and helps it stretch and collapse without kinking.
Pre-attached fittings. Factory-attached fittings are usually more secure than clamps you add yourself.
Included caps for both ends, so the hose stays sealed in storage.

A kit can be simpler than buying parts. The Camco RhinoFLEX 20 ft sewer hose kit we link on our gear page includes a 20-foot hose made of two sections, bayonet fittings, a clear elbow with a 4-in-1 adapter, and storage caps. Whatever brand you choose, make sure the kit has those pieces.

The inlet end: elbows and adapters

At the inlet end, the hose needs to go into the ground opening and stay there. Dump station and campsite inlets vary. Some are threaded (often 3-inch or 4-inch), some are a plain pipe or hole, and some have a hinged cap. Two parts handle this:

Clear elbow

A clear elbow, usually 45° or 90°, turns the hose down into the inlet and lets you see what’s flowing. That matters more than it sounds. You can tell when the black tank has stopped draining, when rinse water runs clear, and whether something is blocking flow. Many elbows also swivel, which makes it easier to line things up without twisting the hose. Some RVers add a second clear fitting at the RV end too, between the outlet and the hose, so they can see flow right at the valve. The Camco clear 45° bayonet adapter and the RhinoFLEX clear 45° swivel fitting are examples of that kind of fitting.

4-in-1 (stepped) adapter

A stepped adapter screws into or seats in several common inlet sizes. It’s often attached to the elbow. With one, you can thread into a threaded inlet, or push it securely into a plain one. Even so, on a plain inlet, put a weight or your foot on the elbow while the tank drains. Flow can push a loose elbow out.

Supports: why slope matters

Gravity does all the work in an RV sewer system. A hose lying flat on the ground, or with dips and sags, holds waste in the low spots. That waste sits there, smells, and spills when you disconnect. A hose support is a folding plastic cradle that holds the hose in a steady downhill slope from the outlet to the inlet. The Camco Sidewinder 10 ft support is a common example.

Supports matter most at a campsite, where the hose stays connected for days. At a quick dump station stop, many people skip them if the inlet is close and the hose runs downhill anyway. If the inlet is far away or the pad is flat, a support helps the hose drain completely.

Rinse caps and inline rinsers

Hose rinse cap. A cap with a garden-hose connection, such as the Camco sewer hose rinse cap, snaps onto the hose’s bayonet end so you can run rinse water straight through the hose before storing it.
Inline tank rinser. A fitting between the RV outlet and hose with a gate valve and spray nozzle, for rigs without a built-in black tank flush. The tank cleaning guide covers when to use one.

Either way, use a dedicated non-potable rinse hose. Some RVers carry a short dedicated one, such as the bright orange Camco RhinoFLEX 10 ft clean-out hose with rinser cap, so it can’t be confused with the drinking hose.

Connecting it all in the right order

Confirm both tank valves are closed.
Remove the RV outlet cap, ideally with the hose end ready below it.
Attach the bayonet end to the RV outlet, twist until it locks, and tug-test.
Attach any extension the same way.
Attach the elbow and adapter to the inlet end and secure it in the inlet.
Set the hose on supports or make sure it slopes steadily downhill.
Now, and only now, open a valve, black first. See the full dump routine.

Storage: keep it clean and separate

Rinse and drain before storing. Lift the hose from the RV end toward the inlet so nothing is left inside.
Cap both ends, or connect them together if your hose allows.
Store separately from fresh-water gear. Many rigs have a bumper tube or a dedicated compartment. A lidded plastic bin works well too. Never put the sewer hose in the same bin as the drinking hose or water filter.
Keep it out of the sun when not in use. UV breaks down the vinyl over time.
In freezing weather, drain it completely. Water left in the hose can freeze and split it. See cold-weather dumping.

Inspecting and replacing

Look over your hose every time you use it. Replace it, or the damaged section, if you see:

Pinholes, splits, or worn-through spots (hold it up to light at home)
Cracking or stiffness, often from sun or cold
A fitting that won’t stay tight, or a gasket that’s missing or flattened
Persistent odor even after rinsing

A hose that fails at the station is a mess. A spare hose or extension in the bin is cheap insurance on a long trip.

Common mistakes

Buying the thinnest hose because it’s cheapest, then puncturing it on the first trip.
Carrying exactly 10 feet and finding the inlet 14 feet away.
Skipping the elbow and trying to hold a bare hose end in the inlet.
Not checking the bayonet gasket.
Storing the sewer hose next to the drinking hose.
Dragging the hose across the pavement.

Problems with a hose at the station? See dump station troubleshooting. For the complete kit, see our dump gear list.

FAQ

What size sewer hose does an RV use?

Most RVs have a 3-inch sewer outlet with a bayonet (lug) fitting, and most RV sewer hoses are 3 inches in diameter. Check your outlet before buying anything unusual.

How long should my RV sewer hose be?

Many RVers carry about 20 feet total, often as a main hose plus an extension, because dump inlets and campsite sewers are not always close to the outlet. Two shorter sections can be easier to handle and store than one long one.

What is a 4-in-1 sewer adapter?

A stepped adapter that fits several common sewer inlet sizes, including threaded and plain openings. It is usually paired with an elbow and helps the hose end stay put in the inlet.

Why use a clear elbow?

So you can see when flow has stopped and when rinse water runs clear. Without it you are guessing when a tank is empty or clean.

How often should I replace my sewer hose?

When it shows cracks, pinholes, stiff spots, or worn-through areas, or if it leaks at a joint you can't fix. Sun, cold, and dragging on pavement all shorten its life. Inspect it every time you use it.

Can I use my sewer hose rinse water hose for drinking water?

No. Keep a dedicated rinse hose, ideally a different color, for sewer work, and never use it for drinking water.

Related guides

How to Use an RV Dump Station (Step by Step)
The full routine, from pulling in to driving off clean: gear, hose order, black then gray, rinse, and pack-up.
Dump Station Troubleshooting: Fixes for Common Problems
Leaks, a hose that won't stay put, no flow, stuck valves, lying sensors, and smells.
First-Time RVer Dump-Day Checklist
A printable checklist: pack, prep, dump, rinse, and pack up, plus first-trip tips.
Cold-Weather Dumping and Freeze Protection
Freezing temps: protect valves and hoses, use RV antifreeze, handle a frozen valve, and find open stations.

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