Dave Solberg

RV Black Water Tank Overview

Dave Solberg
Duration:   3  mins

Description

It is important to understand how to properly empty your RV waste tank system, including knowing the difference between the two tanks and compiling the hoses and tools that make your visits to the dump station easier. In this free lesson, RV expert Dave Solberg conducts a quick overview of the RV waste tank system on his demo basement model vehicle, explaining the proper technique for safe dumping at any campground or city facility and introducing any tools you might need throughout the process.

RV Waste Tank Basics

RV wastewater tanks are classified as black water and gray water systems. The black water tank valve can typically be identified as the larger valve, usually 3 inches in diameter, while the gray water tank valve is smaller, usually 1.5 inches in diameter.

Toilets on an RV are always connected to the black water system, which contains sewage from personal waste. Other water drains onboard are connected to the gray water waste tank, which holds less hazardous water from such sources as sinks and showers. However, depending on the layout, some manufacturers will have the system set up in such a way that the sinks dump into the black tank, but in most vehicles the black water tank will be filled with primarily sewage from the toilet.

Even though the gray RV waste tank holds cleaner waste than the black water tank, you still do not want to dump this tank into the open. Both tanks should be properly emptied at designated dump stations, using equipment that allows for safe and clean dumping.

How to Dump an RV Waste Tank

Before emptying the black RV waste tank on your vehicle you should be sure to put on rubberized gloves to protect yourself against any pathogens. Because it can get messy at the dump station, some people also choose to wear masks to help avoid experiencing the unpleasant smells. Prior to attaching the waste hose to and dumping your black water tank, Dave recommends making sure both valves are closed so you don’t get an unsanitary surprise when taking off the sewer dump cap. Trust us, you don’t want to skip this step!

Next, Dave shows you how to attach the (clean!) dump hose to the bayonet dump valve and empty the black water tank first, followed by the gray one. Emptying the black water and then the gray tank will help flush the hose of the black water sewage with the cleaner of the two water tanks, making it easier to perform the final cleaning with fresh water from the dump station. Additionally, this whole process can be simplified and further sanitized by affixing an extendable hose with an aftermarket funnel. This way, you can run the hose straight through your tank compartment and just drive right over the dump tank.

To make emptying an RV waste tank a breeze, there are several other aftermarket products available such as a clear dump valve connection to see when clean water is coming through the dump valves, and dump hose adapter ends to make an even more secure connection at the dump station. Invest a bit of money, and you’ll never have to worry about a messy cleanup!

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5 Responses to “RV Black Water Tank Overview”

  1. Carroll Cole

    I need to replace the toilet flange. How?

  2. CATHERINE GRAY EDWARDS

    is the black water tank a CLOSED SYSTEM? SHOULD IT LEAK?

  3. Donl

    When we bought our air stream the service manager told us the putting 3 bags of ice down the toilet then driving around while pulling the travel trailer will often help break up any solids that may have lodged in the tank and lines. We were also told that after emptying the black water tank run clean water into the system for 5 minutes leaving the black valve open to help flush out any residue then close black tank.valve and empty gray water tank. Maybe that will help???

  4. Chuck

    I am new to Rving and recently purchased a fifth wheel. Had it a day and yes the seller knew the air conditioners were bad but "forgot" yea right to tell me. Expensive Rookie mistake. Just found out the waste tank is solid clogged. Can anyone please help me with ideas to break up clog without replacing the tank which frankly is too expensive for me right now. All your thoughts and unclogging ideas are GREATLY APPRECIATED. Thanks, Chuck aka idiot Rookie

  5. Chuck Borcher

    I agree with never leaving the Black water value open as the liquid will drain leaving the solid in the tank. However, when we are camping for an extended time, I do leave the gray water value open. I have forgotten the grey water value is closed and after several showers, it has backed up into the shower. I try to anticipate dumping the black water tank and will close the grey water value the night before to accumulate some water to raise the black water from the hose after dumping the black water tank. Then after dumping the black water tank, I will open the grey water value and leave it open.

The sewage system in your RV consists of a black and a gray water tank. Now, typically the toilet is going to be hooked directly to the black water tank. and you can see that underneath here some of them will actually do a black and a gray this one happens to be a little on the lighter color, the blackwater tank so that's the one back here and the gray water tank is going to have a about an inch and a half to two inch. So you get the larger one on the gray water again, this is just the toilet. some manufacturers will dump some sinks in there so every floor plan is a little different kind of depends on the layout of the floor plan how easy this is to get from one place to other. Now the gray water tank is typically just gonna be the shower, your kitchen sinks, your other sink. So it's a little cleaner water. Now. I don't recommend dumping either one out in the open you definitely want to put them in a treated area but the way they do it as we've got a compartment down here, this one happens to be on a basement model that does have some heat that's dumped into here. A lot of times they'll be just stuck underneath there you're gonna to need to protect them in the wintertime, but if you'll hook a hose up, now, if you're going to be camping at a campground for a long period of time I would recommend I'm going to take this out here In fact, before I do that I want to make sure I wear rubberized gloves. I don't want any of the pathogens or anything in there. So we're going to do that. Some people don't like the smell. It, it will get a little messy at times. I have seen people that will literally wear a mask in there to cover the smell so they don't get Irby but you take your dump hose like this. Now this one actually has an aftermarket piece apparatus put on the end, and this is designed to lift up at a dump station, pop it in the plunge hole to then place a lot better than just sticking this down in and kinking the hose. But with this, I can't put it down here it's too big to fit in this hose here Now a little tip before I take this off here this hose did have some stuff in it beforehand so make sure you check and see if anything's in here before you put this up make sure your valves are shut inside and you won't get a, an unexpected surprise but. So we're going to just take this off, twist it off here I'm gonna leave that in there like that. So if I'm going to be camping for an extended period of time, I can just put that down through the bottom like that, and then keep it close. You wanna keep your valves closed all the time because if I have my valves open, when I'm camping at the campground, I'm going to get that smell from underneath coming up into the top. So basically the system works if you want to dump your Blackwater first that's going to be your dirtier water and then dump your gray water after that and the gray water likes to before it's cleaner water at shower and stuff from the sinks that's going to help clean your hose out make it a lot easier to clean.
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