I’m educating myself on the basics of RV parts and mechanics, starting with RV water systems, and the amount of technical information can be overwhelming and confusing. One of my goals is to gather and condense RV system details for easy to understand educational posts.
RV Water Tank Basics
RV water tanks are usually located in the base of a motorhome or trailer. The three types of water tanks are: Fresh Water Tank (Potable/Safe to Drink), Grey Water Tank (Used from Sinks & Showers), and Black Water Tank (Waste from Toilet.)
RV Water Sources
If you’re staying at a campground with water hookups, using city water makes life easier. You don’t have to worry about filling your fresh water tank and you don’t have to listen to the pump running in the middle of the night when someone uses the toilet.
City Water (Hookup): Attach a water pressure regulator to the spigot, an RV drinking water hose to the water pressure regulator, and the other end of the hose to the outside water inlet on your RV. Water goes from the hose directly into the pipes leading to your toilet(s), sink(s) and shower, bypassing the fresh water tank, and eliminating the need to use the water pump.
Fresh Water (No Hookup): Your fresh water tank usually has a separate inlet on the outside of your RV (NOT the city water inlet, unless your RV has a valve that redirects water coming in from the city water inlet to the fresh water tank.) These inlets should be clearly marked on motorhomes and trailers. If you have an older rig, it might be located inside of a compartment on the outside of your RV.
CAUTION: Some RV models have a Tank Flush for flushing out the sewer tank that looks like a fresh water connection. Connecting your water hose to the Tank Flush in error will result in a flooded RV!
Using your own water hose, fill your RV with fresh water until it starts to back out of the overflow hole. Don’t forget to put the cap back on when you’re done.
CAUTION: Never use the non-potable water hose at dump stations to fill your tank. RVers use that hose to stick down their contaminated sewer hose.
Dumping Grey & Black Tanks
Hearing the term “dump your RV black tank” always conjures up images of the well-known movie scene in National Lampoon’s Christmas Vacation… you know the one. Sh______ full!
In all seriousness, dumping RV holding tanks can be a relatively easy and clean process if you have the right tools. We created a checklist that will help you cope with this most dreaded of RV chores.
RV water pumps deliver a certain amount of water per minute. Trailers and campers usually use pumps that produce 3.5 gallons of water per minute, while motorhomes use pumps that provide 5.3 or greater gallons per minute.
Your RV will often bypass the water pump when it’s connected to city water, because city water is already pressurized.
After filling up your freshwater tank, flip the switch labeled ‘Water Pump’ to turn on your water pump. (Some newer RVs don’t require you to turn on your water pump.) You should hear the pump moving water from the tank to fill the pipes in your RV.
When you first turn on your faucet, you might get a sputter caused by air in the pipes, but that should subside once the water pump forces water through all the pipes.
Checking Your RV Water Pump
Find water specifications in your RV manual. (Call a dealer or service center if needed.) Then, take note of the gallons per minute, water pressure, and the dimensions of your current water pump.
You can check your gallons per minute by placing a 1-gallon jug under one of your RV faucets, opening the faucet, and clocking how long it takes to fill. Then, divide that into a minute to calculate your gallons per minute.
To test your water pressure, purchase a water pressure test gauge that allows you to test water pressure in your RV and water coming into your tanks via hookup.
Next, inspect the lines to and from your RV water pump to make sure there aren’t any kinked or pinched waterlines or leaks.
You should replace your water filter prior to purchasing a new pump, unless it’s new.
CAUTION: Turn off your water before changing the filter to avoid getting an unexpected shower.
RV Water Pump Troubleshooting
Read reviews, check forums and talk to your service specialist before you purchase a new water pump. Water pumps are relatively inexpensive, but make sure the pump is actually the problem.
If you plan on replacing the water pump yourself, Amazon is usually the best option to purchase one. You can rely on their delivery time, read reviews, and even ask questions prior to purchase.
RV Water Filters
There should always be a water filter installed between the freshwater tank and the pump itself. Some RVs come with a filter installed in this location. Otherwise, you will have to buy an external filter. Simply attach it between your hose and your RV.
If you’re a ‘germophobe’ (like me), the usual water filter is not going to cut it. You should probably get a UV system. However, a UV system will not remove particles, so you still need to use a prefiltration system to protect your water pump and water lines from sediment.
Winterizing Your RV
Winterizing is not a step that you want to skip if you’re storing your RV in cold weather. Taking shortcuts can leave you with big problems, like water damage and broken pipes. Leaving water in the drain lines can cause cracking when it’s cold.
Read your owner’s manual for unit specific winterizing guidelines and follow the steps in the following checklist that apply to your RV.
Finding Water for Your RV
The website SaniDumps is a dump and water locator that can help you find a location to fill up your RV’s fresh water tank. Options include campgrounds, large gas stations, truck stops, camping stores and fairgrounds.
NOTE: Always call ahead before traveling to a location to avoid wasting time and gas.
Sanitizing Your Fresh Water Tank
Before you use water for the first time, and twice a year thereafter, sanitize your fresh water tank. It’s a fairly easy process, but time consuming.
If you don’t drink water out of your fresh water tank, you might think that you never have to sanitize it. However, if you use water from your fresh water tank for any purpose, you should periodically sanitize the system. This process takes 4 to 8 hours.
Now is a good time to inspect and flush your RV’s Hot Water Heater.
CAUTION: There are several RV Hot Water Tank configurations, so make sure any checklist you use follows the instructions in your owner’s manual for flushing your Hot Water Heater. The main difference between configurations is the existence of an Anode Rod instead of a Plug at the bottom of a Water Heater.
A few supplies that will help to ensure an efficient and safe hot water tank flushing process are:
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