How the RV Water System Works
The RV water system generally works in two ways; by drawing water from an onboard tank through a pump, or by attaching a hose to the RV, and running water from a spigot.
The Onboard Freshwater Tank
The onboard freshwater tank is attached to a water pump, which will pump the water through the kitchen faucet as well as the bathroom sink and shower. The fresh water tank is filled from the outside, using a hose; you should use a special “potable water” hose especially made for RVs. These potable water hoses are free of harmful chemicals that could leach into the water.
Water from a Spigot
If you are parked at an RV park, you can use your hose to attach the RV to a freshwater spigot. There is a hose attachment on the outside of the RV, and the freshwater will flow straight inside. This bypasses the freshwater tank and does not require the pump to be used. If you are using RV park water, turn off the pump. Also, you need to use a “water pressure regulator” if you are attached to a hose at an RV park. RVs do not have hard water pipes, they use plastic hoses. If the water pressure is too high, it can damage these hoses, and possibly flood the RV.
“Gray” Waste Water
The dirty water from the sink and shower will go down into a “gray tank”. You will need to dump this tank down the sewer “dump” when it’s full.
How an RV Toilet Works
RV toilets work in a similar way to a regular toilet; it has some water in the bowl, and it flushes down. The toilet waste goes down into the “black tank” on most American RVs; however, on European RVs, and some American van-style RVs, the waste will go into a “cassette”.
If you have an American RV with a black tank, when it’s full, you will need to dump the waste down the RV sewer dump using a big sewer hose. Please note, always follow dumping the “black water” with dumping the “gray water”. This will help clean out the sewer hose.
If you have a European style cassette toilet, you’ll need to take out the tank and bring it to a dump station. These cassettes are generally 3-5 gallons and have wheels to roll it to the sewer dump. This is much smaller than an American RV black tank and will need to be emptied much more often.
If you are at an RV park, there will probably be a sewer dump at your site. If you are at a state or national park, there will be a dump station that all campers can use. The dump station should also have fresh water to refill your tank.
Finally, RVs also have water heaters that run on propane. These can be turned on and off from a switch.