RV Water Pumps and Fresh Water Systems
So you have an RV. You know there's a way water runs to your sink, toilet and shower. But how? This can be confusing at first as far as knowing how to use 'city water' as opposed to using your RV water pump to access your RV's fresh water tank.
And what about replacing or upgrading your current 12 volt water pump? What is the best RV water pump out there? And what do you need to consider when upgrading your current pump to a stronger one? So. Many. Questions.
Let's face it- it's nice to know HOW the fresh water system in your RV works. We know you don't want to make mistakes or to look like a fool at the campground, so let's knowledge your brain up so that you look like a superstar old-school pro at your first campsite!
RV Water Pumps Compared
RV Water Pump Reviews
There are a few manufacturers of RV water pumps - most of which produce 12 volt water pumps for both the RV and the marine markets. Most 12 volt electric water pumps work basically the same way - they are constant speed pumps that are either on or off. There are a few more expensive RV fresh water pumps that are variable speed, which makes for quieter operation (less, if any, pump cycling or 'hammering') and a constant supply of water (no pulsing).
There are some brands that are more popular in the RV market, including SHURFLO (Pentair) and Aquajet (Remco), while other brands cater more towards the marine market (SEAFLO). We have chosen two RV water pumps for our 'best of' from SHURFLO and one from Aquajet, based on personal experience, consumer reviews, price, popularity and other factors as noted in the below RV water pump reviews.
12 Volt RV Water Pump Installation Considerations
When it comes to installing a 12 volt RV water pump, it may simply be a case of replacing an existing pump with the exact same unit. In this case, it's really just a plug-and-play situation where you are swapping out components.
However, you may be considering upgrading your current water pump to a variable speed one because you want to eliminate the noise and 'hammering' that often accompany the popular constant speed RV water pumps, or you may be wanting to install a higher volume pump. Either of these scenarios may mean the new pump will be rated for more amps than the existing pump, which means you have electrical issues to consider.
And switching from one style (constant speed) to another style (variable speed), or installing a higher volume pump, may present further issues if you have multiple water pump on/off switches in your RV (which utilizes an Intellitec pump controller). Yes there are a few things to ponder before you rip out that old water pump and replace it with a new shiny one. Read on to learn more about possible considerations.
RV Fresh Water System Guide
Water. Can't live without it. Dealing with it in your RV can be a pain (but doesn't have to be).
If you aren't familiar with how your RV's fresh water system works, you might want to learn a thing or two about it. Read on to learn how water gets into your RV, where to find water if you are not at a campsite with a fresh water supply, and maybe even find out a thing or two about those little mechanical things (aka RV water pumps) that facilitate the movement of water through your rig when you aren't 'plugged' into a water supply.
How To Get Running Water In Your RV
Most RVs have two options to get water coming through your RV pipes:
- Attaching a hose to your RV from the outside ('city water')
- Filling up and using the water stored in your fresh water tank
City Water vs. Fresh Water Tank
Using City Water
One way to get water flowing through your faucets is to attach a hose from a spigot to the outside water inlet of your RV. This is what is called using 'city water'. With this method, you don't have to fill your holding tank, or 'fresh water tank'. With the 'city water' method, the water goes from the hose directly into and through the pipes that lead to your toilet, sink(s) and shower. It bypasses the fresh water tank completely.
When using water this way, you can keep the water spigot on all the time. This way, the water pressure from the spigot pushes the water through your pipes, eliminating the need to use your RV water pump. Turning the water off at the spigot when you aren't home is a good option to eliminate disaster if your pipes spring a leak.
Of course, using city water only works if there's a nearby spigot you can use. If you go to a campground and pay for 'full hook-ups', you will have a dedicated spigot to use.
It's a good idea to get a water pressure regulator to attach to your hose. Some parks have pressure that is too high. In such cases, it can bust your water pipes inside your RV. Having a pressure regulator will help prevent this from happening.
Obviously, you can't use city water if you are out in the woods (boondocking) or if you are at a campground that doesn't have water hookups. If that's where you are going, you need to fill your fresh water tank before you get there. That's when your RV water pump comes into play.
Using The Fresh Water Holding Tank In Your RV
Pretty much any RV with a sink or shower in it also has a fresh water holding tank. You will need to use this when you aren't connected to an external water source. You may either fill your tank at home before you hit the road, or you can fill it just before you arrive at your campsite. Also, some campgrounds will have a designated area where you can fill your fresh water tank before settling into your campsite.
If your rig is already close to its GVWR (gross vehicle weight rating), it's best to not drive with your tank full the entire way, depending on how far you have to go.
Driving with your tank full also affects your gas mileage to a certain degree, depending on how large your water tank is. Keep in mind that each gallon of water weighs approximately 8.3 lbs. You do the math for your water tank (capacity in gallons x 8.3).
Of course, driving with a full tank also depends on where you can or cannot get water. Sometimes the nearest fresh water source is no where close to where you are going to camp, so you have no choice but to fill your fresh water tank long before arriving at your final destination.
To fill your tank, locate the outside potable water fill port. Most of the time, it's pretty clearly marked. Here's an example of what yours may look like. Sometimes it's inside a locked compartment, sometimes it's not.
If you have an older RV, just keep looking around the outside compartments until you find a hole that looks like it can fit a hose. It's NOT the same hole that you use to stay hooked up to water like we talked about above. The opening for the fresh water tank fill have a totally separate entry point.
NOTE: Some RVs (mainly motorhomes) do not have a potable water fill port. Instead they have a valve that redirects water coming in from the city water inlet to the fresh water tank.
One other way you can fill your fresh water tank is with portable water containers. You can also fill these to help your water supply go even farther. You then dump them into your portable water fill point (assuming your RV has one). Doing so means you you don't have to move your rig again to top-off your fresh water.
Filling Your Water Tank Using Collapsible Water Containers
Once you have filled up your water tank, you can't just turn on your faucet and expect water to flow. Nope. First, it needs pressure. That's where your RV water pump comes into action. You will need to turn your RV water pump on to use any water when you are not connected to city water. Locate the on/off switch and flip it to the 'on' position. Bingo! You have water pressure.
You can have the pump in the 'on' position, and it won't necessarily be actively pumping. It's designed not to pump until the pressure in your water line drops. The pump is set to keep the PSI in your lines at a certain pressure, usually about 40 psi.
When the pump senses that the pressure drops below that (when you open a faucet) it starts to pump until that pressure is reached. Most (constant speed) RV pumps will pulsate when they are working, that's normal. So if you have water flowing for any duration, the pump will pulse on and off. If you want to lessen the pulsing, you can install an accumulator.
The video below is an example of normal pump operation. You can see that the water pressure fluctuates and if you listen closely, you can hear the pump coming on and off in the background.
There are newer RV water pump models that also claim to lessen the above pulsation and noise. Also, it's a good idea to keep your pump off until you need to use water. This is just in case a leak pops up. You can avoid a big mess. Still, it's personal preference.
Be aware that when you first turn your pump on after filling your tank with water, the lines probably aren't filled with water yet (assuming the tank was previously run dry or had been sitting a while). Therefore, you might hear your pump come on for a couple of seconds to prime the lines. Don't be alarmed, it's perfectly normal stuff. After a short period of time it should stop pumping until you turn on a water fixture (faucet/shower).
Also, your water fixture might sputter and spit the first time you go to use it after filling your tank. This is normal. It will happen until the lines are completely void of air. The water might look weird, sort of whitish. This is again fairly normal and is caused by the air in the plumbing mixing with the water. Once the air has been purged from the water lines, you will no longer hear sputtering or see the air filled water.
You should have your own water hose for filling your rig with fresh, potable water. Fill your rig's fresh water tank until water starts to back out of the overflow hole, then don't forget to put the cap back on.
Never fill your tank using the non-potable water hose at a dump station. People use that hose to stick down their contaminated sewer hose to rinse it. Groooooooooss.
How To Find Water To Fill Your RV Water Tank
Unless you are filling at a campground or at home, it can be a challenge to find water for filling your RV's fresh water tank. There are a few online places that can help. There's a website called SaniDumps that is a dump and water locator. Also, where there's a dump station, there's USUALLY potable water as well. You also may have luck with some of the dump station reviews on the website Campendium (filter for dump stations).
Some gas stations, and the occasional camping store, have fresh or 'potable' water that you can use for free.
Other times you will have to find a campground that will let you fill up. Usually they will charge somewhere from $5 to $20, depending on how greedy they are or what part of the country you are in. Fairgrounds are another place that often has potable water for a price. Use the old-school 'telephone' part of your smartphone to call around. 😆
How Does Your RV Water Pump Get Power?
Obviously your RV water pump needs power to run. Where does it get power from? It's a 12 volt water pump, so it uses your RV's batteries, which provide your RV with 12-volt (DC) power. Even if you are connected to shore power (an outside electrical source) your water pump (as well as all the other 12 volt systems in your rig) will still only run off of 12-volt power.
When connected to shore power, or a 120 volt (AC) source, power goes through your RV converter, which changes the 120 volt power into 12 volt power. Once it's changed to 12 volt, it provides power to all of your 12 volt water pump and other 12 volt appliances. It also charges your batteries. Make sense? Hope so. If not, join the club. Electricity can be a bit of a mystery.
Filtering Your Fresh Water
Should you get a water filter? You might think 'I don't drink the water from my faucets, so I don't need a filter'. Well, that's only partially correct. Filtering the water that comes into your tank also filters the water that goes through your pump.
Filtering water before it goes into your fresh water tank keeps tiny particles out of the pump that might otherwise damage the pump's diaphragm and eventually cause the water pump to stop working. Pumps are not all that expensive, but why have to replace it more often than necessary? You never know how good or bad the water quality is going to be in the new places that you visit. Filter all water you put into your RV.
Some RVs come with a filter installed before the water gets to the pump. Otherwise you will have to buy an external filter. There are simple/good ones that you can easily attach inline between your RV and the water source. A good easy-to-install filter is the Camco 400430 water filter. Simply attach it in between your hose and your RV and you're good to go. It will filter all particles larger than 100 microns. This won't stop things like giardia, but here in the USA, you don't really have to worry about that.
If you are a bit of a 'germophobe' 😆 well, the usual water filter is not going to help you ease your mind. If you are concerned about giardia, bacteria, viruses, cryptosporidium, coliforms, and other biological pathogens you should get a UV system.
A UV system will take care of these things. However, it will not remove any particles so you should also have a pre-filtration system in place if you HAVE to have a UV system. You still need to protect your water pump and water lines from sediment and other particles.
Disinfecting Your Fresh Water Tank
Before you use your water tank for the first time, it's a good idea to disinfect it. Do this ESPECIALLY if you plan to drink the water from your tank. It's also good practice to do this once or twice a year to keep it nice and clean.
How To Sanitize Your Fresh Water Tank
On a side note- we have seen people say you should never put bleach in your tank. The reasoning it that it will mess up seals and the piping. However, we say go with your manufacturer's recommendation. For example, Lance recommends sanitizing your water tank with bleach.
Another tasty morsel of information- to eliminate the bleach smell after sanitizing your fresh water tank, you can add small amount of white vinegar to the tank when you fill it to drain it a second time. You don't have to completely fill the tank, just enough to run sufficient water through the plumbing so you get the vinegar solution through every fixture.
Run all your faucets, hot and cold, until you smell vinegar coming out. Let it sit for a few hours. Then empty your water tank and lines completely and refill with fresh potable water.
Buying A New RV Water Pump
What should you be thinking about when buying a new RV water pump? Don't just get the first RV pump you see. There are a few things to consider.
GPM- you should know how many gallons per minute your pump needs to put out for your specific RV. You don't want to get one that is too powerful, because the bigger and harder working a pump is, the more power it's going to draw from your batteries. Get one too big and it's going to be more of a drain on your RV's electrical system that it has to be.
PSI- should also know what water pressure (pounds per square inch) is recommended for your RV so you can buy the right pressure 12 volt water pump. Though most are in the 'safe' range of 60-75 psi.
Sizing- consider the location of your current 12 volt water pump. In RVs, every square inch of space tends to be utilized, so your pump might be tucked away in a area with little or no extra room. If your current installation is tight, you might not be able to upgrade to a larger capacity water pump as it will physically be larger.
Check your manual for specifications on the flow rate and the maximum water pressure. If you can't find the information, give your manufacturer a call (hopefully they are still in business!).
Installing A New 12 Volt RV Water Pump
Water pumps for your RV aren't very expensive but they can be a real booger to replace. It's not the installation process that's so difficult - usually it's the placement of the darn thing. You may have to be fairly flexible in order to get the job done! Get some good sleep the night before and don't wear anything too irritable for the installation. 😁
Before you start, make sure your water pump power switch is off (this cuts power to your water pump), and then depressurize the system by opening your faucets. Have towels handy as there will still be some water in the lines (and pump) when you disconnect it. Follow the water pump's instructions to make sure the installation is done correctly (duh!).
Replacing an RV Water Pump
Your RV water pump allows you to have running water in your rig without being attached to an outside water source. Extend it's life by always using a water filter to filter the water coming into your RV.
Your RV's fresh water system isn't that complicated, but it's good to know how it works. It's also good to have a basic understanding of how RV water pumps work as you will rely on them when you aren't connected to a city water source.
Replacing an RV water pump isn't the most difficult task one can tackle when it comes to RV maintenance, but it isn't for everyone. If you don't feel comfortable dealing with the wiring that is involved, or you just have two left thumbs, or no thumbs at all, it's probably best to have a professional do the installation for you.
Now that you understand how to use the water system in your RV, you can boondock or dry camp like a champ. Get out there and camp on, Addicts!