Author: Chelsea Barron
One of the most disgusting issues an RV can have is a clogged black tank. After all, nobody wants to deal with what goes down the toilet, especially when it’s so compacted it’s causing a problem. Still, this is fairly common problem, and most new RVers experience it at one time or another.
Fortunately, there are ways to solve this problem without taking your RV into the service center, and once you get it taken care of, there are ways to ensure it doesn’t happen again. Here are our top tips!
Knowing You Have a Clog
Obviously, the first thing you’ll want to do is make sure you actually have a clog. There are a couple of ways to do this. The first and easiest way works only if you have a clear sewer hose or a clear elbow that allows you to see liquid draining from your tank. If only a small trickle escapes when you open the valve, you've got a problem.
Don’t have a clear hose? No problem! Just use your ears. You can hear how much liquid is escaping when you dump, and if it’s only a small amount (or nothing at all) when you know there is liquid in the tank, you can be pretty sure there’s a clog in there.
Attempt a “Power Washing”
So what do you do about a clog? Well, there are actually a few different methods you can use. The first option is to try to “power wash” the clog away using an old water hose (you’ll never want to use this again), plenty of water pressure, and of course, some gloves.
Note that you will not want to try this method if your tank is already almost full as it could cause it to overflow out the toilet—something you definitely don’t want to deal with.
If you have a way to backflush your tank, go ahead and try to wash the clog out using that tool. Otherwise, put the hose down the toilet, turn up the water pressure, and spray in the direction of the clog. In some cases, the water pressure will break up any buildup and send it all down the sewer hose.
For an extra strong spray, try using a product like this.
Related Read: How To Properly Empty Your Black Tank
Try Ice
Unfortunately, the water pressure method doesn’t always work. If that’s the case for you, you might try turning to a couple bags of ice. Dump the ice down your toilet and drive the RV around, making sure to hit bumps and make turns to really slosh the ice around in there.
The idea is that the ice will loosen the clog and then melt, making it easy to dump. Supposedly this works for some, but many others claim it won’t do a thing. If it is going to work, it’ll likely only do so if your tank isn’t completely full since the ice needs need to reach the clog and it can’t do that if it’s floating.
Boil Some Water
Another method that doesn’t require any special tools, but does require a bit of patience (and a clothespin to hold your nose closed) is the boiling water method. We will admit that this method tends to cause some really stinky smells to be released in the rig, but it does work in many cases, making it well worth a try.
Begin by boiling several pots of water. Pour the water down the toilet and let it sit overnight. Attempt to dump the tank in the morning. Sometimes the super hot water is enough to break up a stubborn clog, especially if the tank isn’t already full.
You can always try to use a plumbing snake to break up the clog, but you’ll need to be prepared to get messy and you’ll probably want an assistant.
To start, ensure there is no more liquid trickling from the tank. Next, put a large bucket under the dump pipe to catch any liquid that may escape. Unhook the sewer hose from the RV, leaving the dump valve open. Put the plumbing snake up the dump pipe and feed it into the tank until you hit the clog. Use the snake to loosen the clog and pull it free. This is likely to cause a gush of black water to escape, so have your assistant ready to close the valve as soon as you see any sign of escaping liquid.
With the valve closed, reattach the sewer hose and dump the tank as usual.
Break Out the Chemicals
The problem with most of these methods is that they require the tank to be basically empty or at least only partially full. In some cases, it is possible to get rid of some of the liquid in the tank by allowing it to trickle past the clog. However, if your clog is completely blocking the exit, you may be stuck with a full tank and no way to get rid of water.
In this case—and in the case of a clog that is just too stubborn for any of the methods above—it’s time to break out the chemicals. It is important to purchase an RV tank-compatible product, as most chemical drain-clearing options do not mix well with RV tanks.
Our favorite product to use for this purpose is Aqua-Kem, but any RV tank treatment should help break down solids and cure your clog woes.
Related Read: Is RV Toilet Paper Really Necessary?
When you finally do get your tank cleared of clogs, you’ll want to keep it that way. Here are some simple steps you can take to ensure you don’t have issues in the future:
Use RV-safe toilet paper. Other paper doesn’t break down properly.
Use holding tank treatments with every tank fill-up. The Aqua-Kem mention above is great for this.
Keep the dump valve closed and only dump when your tank is at least ¾ full.
Use plenty of water when you flush. There should always be more water than solids going down the drain.
Rinse your tank between uses.
Related Tags
Cleaning, Plumbing, RV Hacks, RV Repairs / Maintenance / Upgrades, RV Tips, Waste Management
September 28, 2020 | 11:12 AM
We use a large bowl to wash dishes. At least once a week we dump that soapy water down the toilet. Hopefully it will prevent clogging buildups. So far in three years and 25,000 miles we have not had a problem.
August 4, 2020 | 03:14 PM
Here is the solution that we have found to Black Tank issues.... https://youtu.be/Gq3T1fKlV9o