RV Systems – How They Work Part 2

full timers

This article is part 2 of “RV Systems – How They Work” a thorough look at all the systems in your RV and what they do. The systems on some RVs can be complicated while others may be simple. Simple or complicated if you don’t understand how they work you could be in for some frustrating experiences.

In these two articles, I have explained RV systems front to back. I am sure it will help you understand your RV systems better.

Check out part 1 of “RV Systems – How They Work”.


RV Solar Power Systems

Simply put RV solar systems are for charging RV batteries.

For myself, the concept of charging my battery bank and running appliances off a solar panel system is fascinating. Power from the sun, amazingly simple and almost no maintenance, just clean the solar panels occasionally.

The best part of solar power it is a completely renewable resource, zero emissions, and no noise. Solar panels are guaranteed for 25 years, they will actually last indefinitely. The guarantee expires at 25 years because the panels may not produce their specified output after that time.

Solar cells in the solar panels change the sun’s rays into 12-volt DC current. The 12-volt current is fed directly into your RV battery bank through a simple regulator. The number and size of the solar panels are determined by the number of batteries that require charging, and how much sunshine is expected on a regular basis.

Solar panels are sized and sold by the number of watts they produce. This seems strange because it is actually the amps that charge batteries.

For more information on how to determine the size of your RV solar charging system check out my previous article, “Sizing Your RV Solar Charging System”


You’re off the grid.

This is a good starter 200-watt system for charging 1 12-volt or 2, 6-volt batteries. All you need is a 1000 watt inverter and you can watch TV, power up a satellite receiver, charge all your devices and even run a sewing machine.


RV Waste Systems

The first RVs were not equipped toilets, some had a sink but definitely no shower or tub. The first toilet was similar to a porta-potty a toilet seat with a chamber below to hold the goodies.

Most modern RVs have a system very similar to the porta-potty with a toilet and the black water tank directly below, of course, the modern tanks are much bigger. The first RV waste systems had one holding tank for both gray water (sink and shower water) and toilet waste.

I am not sure why the black (toilet waste) and the gray water (sink and shower waste) were segregated, perhaps it was due to weight distribution, but more likely enabling dry campers/boondockers to discard the gray water on the ground or in a hole, without discharging harmful raw sewage.

Even though the gray tanks are mostly soapy water a strong odor may be present when dumping depending how long it has been between dumps and tank flushing.

Lynda and I found this out the hard way. A few years back when parked in the southwest desert near Quartzsite, Arizona, our gray water tank became full but the black water tank was still less than half. I decided to dump the gray water on the ground. What a stink, the odor lingered until we actually had to move to another camping spot. 

Note; some areas do not allow dumping of grey water and of course dumping black water (raw sewage) is illegal except in approved RV dumps and sanitary waste stations.

Many larger RVs have more than one gray water tank. Sinks and the shower drain into the gray water holding tank/s with sloped plumbing pipes (a good reason for a level RV). Beneath sinks and showers are what is called a ‘P’ trap (‘U’ shaped bend in the pipes) this configuration traps water to create an airlock to prevent air/odor from coming up the drain from the holding tanks.

Grey water tanks require a vent, usually a pipe to the roof with a cap, allowing air to escape as water flows in. Some RVs that have kitchen islands have a one-way air valve under the island sink. This ingenious invention allows air into the drain without letting the smell out.

The black water tank, although the simplest design seems to cause the most issues usually related to clogging. The black tank is usually located directly below the toilet. The sewer dump hose attaches to the black water tank drain pipe.

Clogging problems can be avoided by keeping the drain valve closed until the black water tank is full. Most modern RVs have a black tank flushing system, this works well to keep your black tank clean. If your RV is not equipped with this feature a special flushing sewer pipe attachment is available.

The gray water tank drain pipes feed into the larger black water pipe drain located on the driver’s side of the RV. The gate valves for draining are located near the large drain pipe usually close to the docking station (city water connection). The closest and largest valve handle is the black water tank gate valve. The others are gray water valves.

When dumping open the black water drain valve first. Open the valve SLOWLY to reduce the force of waste coming into the flexible sewer hose otherwise, you take the chance of having a literal shit show, with the sewer pipe jumping out of the drain hole. “Been there done that!”

Dumping the gray water last helps flush the black water from the sewer hose.


Heating and Air Conditioning Systems.

Modern RVs are equipped with ducted heating and air conditioning. Controlling the two systems may be with one control/thermostat or two. Heat is ducted under the floor with several outlets (heat registers) generally in each room. I normally keep the bedroom registers closed to keep the bedroom cool and adding more heat to the living area.

The air conditioning is ducted through the ceiling with vents throughout the RV, again the vents may be closed in areas to supply more cool air where desired. Some systems allow for the A/C fan operation only, to increase air circulation. Furnaces and air conditioners generally have air filters that require periodic cleaning.

Many RVs come equipped with a 12-volt DC ceiling vent fan. Normally these fans are variable speed and reversible to provide inflowing or outflowing air. Great for cooling off your RV. Some ceiling vent fans have a rain sensor that closes the vent automatically. In some 5th wheel trailers with high ceilings, the ceiling vent fan is operated by a remote control.


Exterior Systems

Slide Outs

Probably the most important improvement in RVs in recent years. The slide out turns a long narrow bus type configuration into a more useable and attractive rectangular shape.

Slide outs are operated by a system of tracks, gears, and a12-volt electric motor. If the electric motor fails or the RV battery bank goes dead it is possible to manually bring in the slide. This mechanism is usually located under the RV on the opposite side of the slide. There may be a special tool required for this purpose.


Newer RVs are equipped with 12-volt powered awnings, some have wind and rain sensors that will automatically retract if the wind or rain becomes too intense.

Slide toppers (automatic awnings attached to the top of slide-outs) may also be included on an RV, these provide protection from rain and debris landing on the slide top. It is a good idea to check the top of your slide/s for debris or water before retracting them. Even if your slides are equipped with toppers water and debris can accumulate on the top of the slide under the topper.

On one of our RV trips in our motorhome, it rained the night before we headed home. I neglected to check the top of the slide before retracting it. The slide retracted directly behind my driver’s seat.

My first application of the brakes brought a cascade of water down my back soaking me and my seat, quite a shock. Slide toppers were immediately added to the slides and inspections are always carried out before slide retraction. School of hard knocks.

Stabilizing Sytems

All modern RVs have some sort of stabilizing system that may be deployed while parked. A stabilizing system lessens RV movement allowing people to move around without rocking the boat, so to speak. These are generally located near each of the exterior four corners.

Stabilizing Sytems may be manual or powered. Manual systems are usually found on smaller less expensive travel trailers, usually a scissor jack style with a screw type mechanism. The jacks may be operated by hand or some campers use a cordless drill. These types of systems are not intended to lift the RV.

Larger travel trailers, 5th wheels, and motorhomes often have electric or hydraulic stabilizing systems. These systems are operated by 12-volt motors or a 12-volt hydraulic pump. Hydraulic systems are the ultimate stabilizing system and can be used to stabilize as well as lift and level your RV. A hydraulic leveling system is not only easier but much faster to deploy. They also keep your RV more stable.


Outside Kitchen

Many newer RVs are equipped with outside kitchens usually located at the right side rear. These kitchens contain a small stove, small fridge, sink and maybe a barbecue. The larger RVs may have an outside TV that may be included in the outside kitchen.


Most modern RVs come equipped with a barbecue mount somewhere on the exterior and also an exterior propane connection.

TV Antenna & Satellite Systems

All RVs these days are equipped with some sort of TV antenna. The roof-mounted crank up style is the most popular. This type of antenna works well with a directional swivel and a 12-volt booster for tuning in local TV stations. The booster switch is located at an electrical cover plate usually with a light indicating on or off.

In recent years satellite TV systems have become more popular with more reasonable prices. We use a tripod-mounted satellite dish placed on the ground with an unobstructed view of the southern sky.

This system is easy to use once you have some practice finding the proper satellite. The procedure is as follows –

  1. Place the satellite dish (tripod) with an unobstructed view of the southern sky ( no trees).
  2. Connect the satellite cable to the dish head and receiver.
  3. Check with your TV satellite company for the name of your system’s satellite.
  4. Check with your owner’s manual or satellite company for setting up the receiver settings.
  5. Obtain satellite coordinates from your satellite TV subscriber or the internet, “point dish” or some other site.
  6. Set your dish elevation and using a compass set the direction.
  7. Use a satellite finder to fine tune the dish.


The easiest satellite systems are automatic systems. These are mounted on your RV or not. The only preparation required is not to park under a tree. Turn on the satellite system and the dish automatically searches for the correct satellite.

There are also tailgate satellite TV systems, simple to use.


There could be several more systems in your RV depending on whether you own a towable or motorhome, including mechanical systems on motorhomes, braking and hitch systems on towables.

Check out a previous article on trailer brakes and hitches “Choosing the Right Hitch“.

I  have covered most of the popular RV systems. There are probably many more systems available for your RV and no doubt many more to come. From what I have seen and experienced the more systems the more issues you may have.

If you are in the market for an RV my advice is to test each system in the RV, if possible, before you sign the sales contract. I know of many cases where the purchaser has bought an RV and has had so many problems that could not be resolved they have tried to return the RV.

 3 New RV ebooks

Two are RV Guides, one is an entertaining account of our travels.

Available for instant download on Amazon they cost less than a fancy coffee.

“The RV Buyers Guide”

Read how 40 years of owning RVs will help you decide which RV model is right for you.

Take advantage of my limited time offer.

Download in seconds from Amazon.

Choosing an RV is a complicated task, there are many models and sizes to choose from. If you have never owned an RV the task could be confusing and frustrating.

Lynda and I have owned an RV for over 40 years, during our time we have owned almost all RV models from a small tent trailer to a large 36 ft. class ‘A’ motorhome.

In this book, “The RV Buyers Guide”, I have put together what we’ve learned about each RV model to help you with the process of deciding which one will be best suited for you and your family’s lifestyle.

Whether you are contemplating RVing with the whole family on weekend excursions and the annual family vacation, or retiring and considering traveling with your RV or maybe you already own an RV and considering upgrading, there is plenty of information in this book .

For less than a fancy coffee, $2.99 you can own this great guide to choosing which RV model is right for you.

Get your copy today

Check out my other ebooks


5 true stories of our RV travel experiences.

These stories will keep you glued to your seat and make you laugh till you cry.


From Conception to Destination.

A travel guide that will help you avoid the common pitfalls of travel.

From securing your home and packing to renting a car.

Containing comprehensive lists for planning.

Thanks for visiting, Happy Trails

Gord B.








Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.