RV Basics : RV Plumbing System Basics

Last updated on November 11th, 2024 at 05:32 pm

April 27, 2010 by Marlan at Rv52 6 Comments

Essential RV Plumbing Guide for Beginners: Tanks, Tips, and Top Concerns

Understanding RV Plumbing Basics

If you’re new to RVing, understanding your RV’s plumbing system is essential. This guide provides an overview tailored for beginners who may not be familiar with RVs, helping you get a handle on the basics of maintaining and using your RV plumbing system effectively.

Why RV Plumbing is Different

RVs are designed for flexibility, allowing you to camp without hookups for a few days, commonly referred to as “boondocking” or “dry camping.” To make this possible, RV plumbing systems are designed with three main tanks:

Fresh Water Tank – Holds clean water for drinking, cooking, and other uses.
Gray Water Tank – Collects “used” water from sinks and showers.
Black Water Tank – Holds wastewater from the toilet.

Each tank serves a unique purpose, and proper maintenance is crucial to ensure smooth operation while camping.

Key Components of RV Plumbing

Fresh Water Tank

The fresh water tank stores potable water for your RV when you’re not hooked up to an external water source. Since this is the water you’ll use for drinking, cooking, and cleaning, it’s essential to keep it clean. Use only approved methods to sanitize and treat the fresh water tank. A built-in pump provides water pressure to this system, so you can still use it when dry camping.

Gray Water Tank

The gray water tank holds water that drains from sinks and showers, which fills up surprisingly fast. Many RVers use gray water to help flush the black tank during cleaning, but when connected to a sewer or septic hookup, you can leave the gray water tank valve open to prevent overflow.

Black Water Tank

The black water tank holds waste from the toilet and requires a different approach. Keep the valve closed until you’re ready to empty it. Flushing the tank all at once helps prevent waste buildup, which could block sensors and cause inaccurate readings. Adding enzyme treatments can help keep the tank clean, but note that these additives don’t treat the waste—they just assist in preventing residue buildup. Be sure to use RV-friendly, quick-dissolving toilet paper to avoid clogs.

Top 5 Concerns About RV Plumbing Systems

After analyzing common questions and concerns about RV plumbing systems, here are the top issues RV owners face:

Tank Odor Control – Keeping unpleasant odors from black and gray tanks at bay is a major concern. Enzyme treatments and regular cleaning are essential for odor management.
Tank Sensor Malfunctions – Residue buildup can cause inaccurate readings, particularly in the black tank. Regular flushing and cleaning help sensors work properly.
Clog Prevention in Black Tank – Using only RV-safe toilet paper and avoiding certain waste products can prevent clogs that block drains or impact flushing.
Gray Tank Overflow – Gray tanks can fill faster than expected, especially with frequent shower and sink use. Knowing when to empty or open the gray tank valve is key.
Sanitizing the Fresh Water Tank – Since this water is for drinking, proper sanitization is a top priority. It’s crucial to regularly clean the tank to prevent contamination.

Understanding these key points will help you manage your RV plumbing system and avoid common issues. With proper maintenance, you’ll enjoy a hassle-free experience, whether you’re camping off-grid or at a full-hookup site.

RV Basics : LP Propane Pressure Gauge tank meter

Last updated on August 31st, 2016 at 07:31 am

April 14, 2010 by Marlan at Rv52 Leave a Comment

When Puma the RV came new, it came installed with two 20 gallon LP gas tanks. They are mounted on the front of Puma on the hitch – the advantage being that they are easy to access, which is true.

Each tank has a hose that goes from the tank to basically a switch which allows you to quickly switch between either tank. The idea behind that is you switch to the full tank then disconnect and fill the empty tank which makes total sense to me.

On the ‘switch’ or LP gas control switch is a little red ‘window’ which I believe is supposed to help you know if the tank is empty or not. I’ve never seen the window show anything but a dark red color no matter what. So it either does not work… or something. Anyway, it just isn’t tactile enough for me.

So Sheri and I decided to get a simple gauge, which I believe is as simple as a lp propane pressure gauge. This would help us get a better idea if the tank was empty or not. We purchased it at home depot for $16 and the link above was to a similar one on Amazozn. We probably should have gotten two, but we got one instead.

We’ll let you know how that goes and how it works over the course of the next few months and update THIS ARTICLE – not a new one. Unless a new article would be useful to describe a new concept that greatly changes or expands this one.

Amazon Listings for RV Propane Tank Meters:

CLICK HERE IF YOU DO NOT SEE A NICE SET OF AMAZON SEARCH TERMS RELATED TO rv propane gauge BELOW

RV Basics : Black Water or Sewer System Information

Last updated on June 26th, 2019 at 04:33 pm

April 13, 2010 by Marlan at Rv52 Leave a Comment

The RV sewer system and holding tank wiring and plumbing are one of the most discussed and lamented systems on the RV.

Typical RV Sewer System with holding tank wiring Diagram

A simplified typical RV sewer system showing holding tank wiring

In the typical modern RV sewer system you really only have the toilet pipe going straight into a black tank. The black tank is piped to a drain valve that has the large blade. You can open and close the valve easily with the large pull tab. That valve then flows out the exit portal into a stinky slinky. In turn, the slinky is connected to an external receptacle. The receptacles is usually a plumbing fitting going into a septic tank or city sewer.

The holding tank monitor has probes at 1/3, 2/3, and full. These probes will then sense a water level at each probe. These probes are wired back to a monitor. This monitor will have a set of wires for each tank. The simple theory of operation is that water touching the probe will demonstrate a higher signal level that can be detected. This works somewhat in most tanks but the black. (See below for more)

Why do the blank tank monitors get stuck at certain levels?

We have yet another little mystery with Puma. The black water indicator is STUCK at 2/3 full and there is very little we can seem to do to get it unstuck. If you understand (read below) that the monitors are like little probes with a plus (+) and a minus (-) then that is step 1 to understanding. Step 2 is realizing that the black tank is the one tank where the water has debris of all yukky types in the tank.

So what happens is that the debris, whatever it is, clings to the probe ACROSS the plus-minus ( + – ) connection making the probe think the overall level of stuff is at that probe when in all actuality the true level is much lower.

Do black tank rinse systems improve the reliability of the black tank monitors

Our Open Range (we had after Puma) had a black tank rinse which should have helped the sticky probes, but I don’t think it did. With the black tanks we relied on the nose and the sound of the toilets.

What do the typical black tanks look like?

My first question is what do the black water holding tanks look like? I found a page that has many pictures of the black water holding tanks and I think this is probably very representative of what most black water or sewer holding tanks look like.

CLICK HERE IF YOU DO NOT SEE A NICE SET OF AMAZON SEARCH TERMS RELATED TO rv holding tank BELOW

I found a very good selection of Black Water Holding Tanks from Camping World.

Walmart only had the portable RV holding tanks which is different from the rv sewer system we’re describing here.

Holding tank wiring and monitoring systems

On our PUMA, I can’t say for sure, but I’m pretty sure that the tank monitoring unit is from KIB and what I’m showing is an almost perfect copy of our unit :

I found the following wiring diagram on the kib web site. You can get a PDF, but I show just the section that shows the wiring of the black water (sewer) tank sensor system :

black tank wiring for monitoring level — black tank wiring or holding tank wiring for monitoring level

(I’m hoping you can blow it up by clicking on it) .

How a SIMPLE black tank monitoring system works

How the sensor system seems to work : It looks like this is as simple as a wiring system that has a ground and then three wires at different levels in the tank. When the “lovely goo” level raises in the tank, it contacts a wire and then reads a lower resistance than when the substance isn’t in contact with the wire. This seems notoriously unreliable. But now I have something I can work with to see if the sensor is just covered up or broken.

My observation is that as near as I can tell, the sensors not working well for the black water are a pretty common problem.

Alternative ways of sensing tank levels.

I also think there are other methods like capacitive sensing, RF sensing, ultrasonic sensing as well as the resistive. A quick search on the web yields several systems quite easily.

A possible method of making your tank easier for the gunk to slide out

One other thing we’re going to do is to start using a little water softener in our black tank. It doesn’t look harmful and it is supposed to make your tank ‘slickery’ which helps the debris sluice on out. This is called the geo method, or at least part of it for sure.

We don’t want to use many chemicals, but we thought water softener seems like a simple/good idea. This article isn’t about black water tank care, but just about simple facts about black water tanks. I have found that there just isn’t info ABOUT the tanks, but there is lots about caring for the tanks.

You can find lots more information about rv black water on my RV52 how to page. There is a ton of crap (ha ha – I mean information) on that page.

Since I’ve been a bit more on the monitoring/electronics side of the holding tanks, I thought I would put some Amazon listings that are relevant to monitoring systems next.

CLICK HERE IF YOU DO NOT SEE A NICE SET OF AMAZON SEARCH TERMS RELATED TO rv holding tank monitor BELOW

Is an RV a Good Investment?

Last updated on October 21st, 2012 at 12:40 pm

January 3, 2010 by Marlan at Rv52 Leave a Comment

UPDATE : This article has been greatly expanded and made into a FREE ebook. Find out how to get the FREE ebook -> here <-.

This probably could be very controversial but I wondered if an RV is a good investment? I know it depreciates and homes appreciate, but what do the NUMBERS say?

I had to start with “Is an RV a good investment” and add “compared to what I’m doing now”.

So, THIS LINK is a google docs spreadsheet.

I make some ASSUMPTIONS (please be gentle oh blogosphere). I started with the idea that I am doing something now – say rent @ $1,400 per month. I then decided my choice was to buy a house or buy an RV and I compared the three. I assumed a savings rate, a mortgage rate, pad expense (for the RV), real estate taxes. I ignored the idea of an RV loan, although it is not out of the question, AND you even get a mortgage deduction with an RV loan. The one thing you don’t get is property tax which may make beating the standard deduction difficult.

What was suprising… is RENT is the absolute WORST path no matter what – not even close. But surprisingly, house and RV were not that far apart in ‘end point final assets’, but for ENTIRELY different reasons.

I left out some details like fuel costs for heating and cooling or rv insurance or home insurance as they needed to be purchased on both options. Anyway, just meant this to be FUN and thought provoking.

Marlan