What is a Sewer Donut for RV? It’s a simple rubber doohickey that seals the connection to the sewer and sewer hose.
In this post, we cover what the sewer donut is, how it works, how to connect to a septic tank and a couple of other FAQs related to the RV sewer system.

Ok, What is a Sewer Donut For RV?
A sewer donut is a round rubber device used to seal off the ground sewer connection.
When you do a straight connection between that hole and your black water sewer pipe there can be air gaps. When there are those gaps, the odor, etc., escapes and makes the surrounding area unpleasant.
Once you place the doughnut in the sewer hole and then your connector on the waste line, those gaps are supposed to be sealed and no more foul odor escapes. These doughnuts are round, made of rubber, and have a tapered end so that they will fit into any waste hole you encounter.
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How Does A Sewer Donut Work?
Just place the tapered end in the campground sewer hole and then place your waste pipe inside the other end. This round, rubber-shaped device seals off any gaps and keeps odors from escaping and annoying those around you.
The only real requirement is to make sure you get the tapered end inside the campground’s sewer hole and not the other way around.
There are no motors, no controls, no buttons to push, or codes to remember. Operating this sewer doughnut is as old school as it gets. Just take it out of its storage spot, place the tapered end into the hole, and then your waste line on the other side and you are done.
Just make sure to give it a rinse or two to make sure there is nothing left on the rubber to smell up your RV storage area. When you are done, you just put it back where you got it from.
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Are All RV Sewer Hoses the Same Size?
You can get an RV today, or rent one, that has sewer hoses that are the same size. They are 3-inch diameter drain hoses that come with bayonet-style fittings to connect to your Camper or RV. The diameter is standardized, so is the way they are connected, RV sewer hoses are universal and should fit any modern Rig.
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How Do I Connect My RV to my Septic Permanently?
If you are fully modernized, you may be a bit confused about how this low-tech item can operate. The device is not hard to use and it just takes a little common sense and logic to figure out which end goes where.
The tapered end goes into the sewer hole firmly, then you insert your waste hose and make sure the connection is tight and secure. That is it. If you’re staying at a full-service campground, the key to using one of these items is to remember to pick it up, clean it off, and put it back into storage before you leave for your next destination.
While they are not expensive to purchase, it is an extra expense you can do without. Cleaning it off helps keep your storage area smelling nice and be germ-free
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How Do I Hook Up my RV to PVC sewer?
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How Often Do You Have To Empty RV? Dump your holding tanks every 3-5 days. Dumping this often reduces the likelihood of waste buildup that could cause clogs, poop pyramids, odors, or misreading sensors.
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Wrapping UP: What is a Sewer Donut for RV?
So, What is a Sewer Donut for RV? it is your friend that will prevent you from getting into an icky situation.
Many RV parks and campsites do not have a threaded sewer connection. The threaded version comes in handy as it makes an excellent tight and secure seal. When it doesn’t have this style, you need to use a doughnut. It is law in some states.