How Do You Bypass an RV Holding Tank?

RVs are becoming an incredible way to spend leisure time and to get in touch with nature. Many are jumping on the RV bandwagon to experience what the fuss is all about. This explains both the rising sales and rents of recreational vehicles the like of which no one had expected before. However, vehicles like RVs come with their challenges. The unique nature of their challenges makes it important to have the know-how to navigate through them.

One such problem is to figure out a way to bypass the RV’s holding tank. This need can arise when there is no dumping place nearby and the tank is full to the brim. This blog aims to provide you with the necessary tips so that you easily bypass your RV’s holding tank when the need arises.

The Catch

Before we start discussing various options to bypass an RV holding tank, it is worth mentioning that some options would affect the resale value of your RV. Recreational vehicles are high in demand these days and some options to circumvent the holding tank would likely have a considerable effect on the resale value. Such options include getting rid of RV’s toilet and using permanent bypass mechanisms. Though, on the plus side, you will get to enjoy your days without the hassle of constantly worrying about the holding tank.

Replace with a Residential Toilet

One way to eliminate the holding tank from the equation without having to ponder over ways to bypass is to use a residential toilet. A run-of-the-mill residential toilet doesn’t work the same way as an RV toilet or a commode but it certainly gets rid of the black tank. Residential commodes are equipped with a p-trap or a siphon pipe that blocks sewer gases. The blockage of sewer gases keeps the pungent odor out of your RV.

However, there is a huge catch to using a residential toilet. Contrary to RV-style commodes, residential toilets gulp chunks of water. Camper vans have limited water storage ability and aside from toilet, water is also needed for washing dishes, drinking water, and bathing.

Use an Electric Macerator Toilet

Another type of toilet that is well suited to eliminate black tank is the electric macerator toilet. Macerator toilets and centrifugal toilets are sometimes used interchangeably. These kinds of toilets are equipped with an eco-flush facility which reduces the usage of water. This together with their ability to push solid waste to a distance makes them a good contender for anyone looking to find their way around the holding tank. The only major downside of this option is the cost. Expect to spend $1000 or more when shopping for a macerator toilet.

Composting Toilet

One less popular way of bypassing an RV holding tank is to use a composting toilet. As the name suggests, it composts solid waste which can then be used for fertilizing soil. Such toilets also use little to no water which is why they are often referred to as dry toilets. Compost toilets are relatively affordable and don’t require constant look after.

Though, a carbon additive such as sawdust, coconut coir, or peat moss needs to be added after each use.

Enzyme Drain Cleaners

Enzyme drain cleaners are somewhat similar to composting toilets. The enzymes gradually thicken up the waste material allowing for easy removal at a later stage. The live microorganisms consume the organic matter and turn it into a material that is easy to remove. The catch here is that you shouldn’t frequently use these treatment options as they can seriously damage the system over time.

Using PVC Pipes

For RVs that are stationary for a long time or are on their 5th wheel for longer periods, running a 3” PVC pipe to the sewer connection can be a better idea than using a sewer hose. This will eliminate the hassle of having to dump the tank all the time. However, to make this method work, you’ll need to have a bit of experience in DIY stuff. Remember that if you are using the holding tank with the PVC pipe, then always keep the valve closed until there is a need to dump and flush. Keeping it open all the time will allow sewer gases to penetrate your RV and it will also lead to solid waste getting accumulated in the holding tank.

Diverter Valve

Another similar solution to using PVC pipes is to use a diverter valve. Using a diverter valve, you can select whether the waste goes to the tank or directly into a sewer line. The method is cheap and doesn’t take quite as much time as you would think.

Though, you may have a difficult time fitting the diverter valve underneath an RV as it takes considerable space.

Detach the Vent Pipe

Almost every holding tank contains a vent pipe that acts as a barrier between contents and other pipes. Removing this vent pipe would get rid of some of the water in the holding tank. Once done, remember to attach the vent pipe back into its place. Allow the air to refill it and then the drain system would be ready for normal usage.

Utilizing the Water Heater Bypass Valve

Surprisingly, the water heater of a camper van is usually attached to the holding tank. Therefore, circumventing the water heater is one way of emptying the black/holding tank much faster.

Toilet Paper

Toilet papers are often responsible for choking toilets which can lead to a mess. Though, this also creates a somewhat creative solution to bypass the holding tank. Pumping enough toilet paper down the toilet will block up the drain valve and thereby allow you to empty the black tank. As you’ve might guessed, the solution is a rather messy one so it’s better to leave it as a last resort.

Using Baking Soda

Baking soda can be used for a variety of purposes and surprisingly it can also be used to bypass the holding tank. Though, you will need to make sure the tank is only half full so that the soda can do its thing efficiently. Add half a cup of baking soda followed by vinegar or any good drain cleaner into the top opening of the black water valve. Both the chemicals would react to break down the waste accumulated in the tank which, in turn, would allow for easier removal of waste.

A Difficult but a Doable Approach

A water heater bypass valve seems like a metal knob or a handle and is located underneath an RV. It can usually be found between the fresh water tank and the kitchen faucet. Once located, turn off the power supply so there’s no risk of injury. When bypassing the holding tank, you will need to turn off this valve as well as the water supply that comes in from underneath the RV.

Afterward, use a container below the hose and turn the handle to its original position. As soon as the handle/knob is turned, water/waste will start flowing out.

Water or RV Antifreeze

You can use either water or antifreeze to empty the holding tank, but antifreeze would be the way to go if a quick drain is what you are after. Pour water or a diluted antifreeze into the blackwater’s top valve to avoid damage. Only use an optimal amount of both water or antifreeze as too little or too much of both would lead to an undesirable situation.


The main reason behind the foul odor from the toilet or the black tank is a clog. The clog can either be in the hose or the dump valves.

Be sure not to allow solid waste into the drain valve. Also, ensure that the waste does not spill outside and goes where it is intended to.

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Ever since I was a kid, I've been fascinated by travel. I inherited this passion from my parents. Since my college years and to this day, I have had a passion for traveling in a motorhome. I am here to share my experiences with you.

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