How to Unclog a RV Toilet Holding Tank

If you are new to traveling around in an RV, you try to have all the creature comforts of home. Besides the common issues you may encounter, such as flat tires or a dead battery, there is one thing you need to deal with at some stage of your journeys.

What do you do when your black water holding tank won’t drain? It can leave you in a sticky situation when on the road, so you do need to know how to deal with it. An RV toilet is very different to a regular toilet, so you need a different set of skills.

Here you can learn all you need to know about tank maintenance and how to clear an RV clogged toilet with the least effort using various methods.

Unclog RV Toilet Tips

What Causes RV Toilets to Clog

Before you understand how to clear your holding tank, you need to understand what causes the issue.

In most cases, two things lead to a black water tank clogging. Solid waste from toilet users and excessive amounts of toilet paper.

How Not to Clean Your Black Water Tank

While some individuals do say these methods are effective, you are better avoiding them for a couple of reasons. One is you can damage your toilet tank, and second, you may find yourself covered in human feces and waste.

  • Never use a pressure washer: It sounds logical to do so, yet you have that initial backpressure, and it can only go in one direction.
  • Don’t use pressurized air: When trying this method, you can push the blockage harder into a corner, or you can have the same issue as above, and you need to duck quickly.

How to Unclog a RV Toilet Holding Tank

You do have to determine the cause of the clogged RV toilet before you can unclog your RV toilet. Now you understand these toilets are not the same as at home, you can go about your business.

Here are the step-by-step instructions on how you unclog an RV toilet.

1. Wipe Down Your Line

Hardened waste accumulates around your wastewater line, which connects the toilets to the holding tank (for full-time RVers, this may be a worse issue).

Take a manual toilet snake so as not to puncture the wall of your tank. Push down the length of the pipes until you find any resistance.

An alternative method is to fill your black water tank with a mixture of liquid soap and water to the half-level mark. Some RVers use half dish soap and water softener and then add a pot of boiling water (let sit overnight).

Drive your travel trailer around on a rough road so the soapy water can dislodge any hard material. (Learn How Do RV Refrigerators Work)

Once done, flush the toilet pipes with water and let the tank sit for a while. You can rewash the line after a few more hours.

2. Test Tank Valves

After taking care of your tank, you may still have a clogged toilet. Now you need to test your valves to be sure everything can flow as it’s supposed to.

Many new RVers forget to open all the correct valves so that double-checking could save some work. Toilet tank valve open at this stage is the way to go.

Walex CMDOBG Commando Black Holding Tank Cleaner Drop-Ins, Ocean Mist Scent (1 Year Supply)

3. Chemical Treatments

It is possible to purchase chemical tank treatments. It may be these do the job quicker and more efficiently than you can manually. However, you do need to understand a couple of things before you purchase any bottle.

When searching for the best RV holding tank treatment, you may come across the Unique Black water tank cleaner. While a little costly, it can save tons of effort and does offer other benefits.

  • You don’t need to drive around
  • Liquefies solid matter, pyramid plugs (piles of poop), and toilet paper overnight
  • Safe for a septic system and sewer line (eco-friendly and non-toxic)

While there are many around, using a septic-safe product is vital. In addition, you do need to follow their method of working your toilet.

The first rule, keeping your ‘valve closed,’ and the reason being waste and wastewater inside your holding tanks slosh around and break up the hard matter. Dry campers (Boondockers) use this method and rarely face the issue of an RV black tank clogged. (Learn How To Paint RV Exterior Fiberglass)

You will find this kind of black water tank cleaner has one tank treatment per bottle. It also complies with most state regulations.

Alternative RV Toilet Unblocking

You can find many more methods to treat a toilet clog; however, using a hose or a toilet snake may not be suitable if you are nowhere near a water source.

Also, while you ought to keep a bottle of the tank cleaner as mentioned above, there are times before you know of it, you could face a blockage. (Find the Best RV Waste Tank Portable)

  1. One other method, which is proven, is the ice cube method. Using the cube method, you need to make sure you have water to the 1/3 full level.
  2. Then, you need to fill the rest of your tank with lots of ice cubes. It may be more than you can cope with, so find a store that has ice cubes for sale.
  3. Make sure your tank valve is off and then set off driving, try to pick rougher roads so the cubes can loosen all the stubborn waste.
  4. By the time the ice melts, you ought to be able to arrive at a dump station and find out your tank is free from any clog or blockage.

To make sure you don’t suffer clogs again, it is better to prevent your RV toilet from clogging in the first place. (Read Dometic RV Air Conditioner Troubleshooting)

The chemical cleaner is suitable for occasional use to make sure you are free from a pyramid plug building up, or you can flush some hot water down your toilet before cleaning your tank to make sure they are all clean.

Read more:

How to Unclog a RV Toilet Holding Tank

Scroll to Top