How to Fill Up the Fresh Water Tank in Your RV, Motorhome or Camper

rv fresh water tank

Having access to fresh drinking water in your RV makes all the difference when you’re on the road or at a campsite.

Sometimes you can hook your motorhome up to an external water supply directly, but there are bound to be some occasions when you’re reliant on your fresh water tank.

It’s something I always pay close attention to and ensure we’re not in danger of running low on water (especially if the kids are about to have their showers!)

In this handy guide, I’ve included everything you need to know about filling up your RV or camper freshwater tank.

RV and Motorhome Water Tanks

It’s worth noting the different water tanks on your RV. As well as identifying the fresh water tank, you should become familar with the “grey” and “black” tanks. These tanks store very different types of water so you don’t want to get them confused!

Freshwater Tank

This is your “fresh” water supply. This is used for drinking, showers and any taps in your RV. It is clean, and safe to drink.

Greywater Tank

The grey water is the waste water from the freshwater supply. For example, the water that goes down the sink, or shower. Food or dirt may have contaminated it, so it isn’t suitable to drink anymore.

Wastewater (Black) Tank

This is waste from your toilet. Some RV’s may combine the wastewater tank and the greywater tank. For obvious reasons, you don’t want to confuse your freshwaster tank with your wastewater tank!

Checking Your Freshwater Tank Level

Most RV’s and motorhomes will have a gauge that allows you to check the level of the freshwater. If not, you may have to check it manually.

Many tanks will have recommendations for when to refill the tank.

How to Fill Your RV Freshwater Tank

To fill a fresh water tank, you need to turn off the water supply valve (normally the left tap).

You can fill the fresh water tank from the hose or manually from a tap at the campsite.

Open the drain valve on the floor of the fresh water tank. You will often have to open a second valve on the bottom of the fresh water tank.

Connect the hose to the fresh water tank and then, turn on the water supply. Open the hose tap and let all the air escape. Turn on the hose tap (on the end farthest from the well) and then open the hose tap closer to the water source, only enough until the water starts coming out. Close the closer tap and turn the other tap off.

Let the hose fill up about halfway and turn off the tap.

How Long Does it take to Fill Freshwater Tank?

This really depends on the make and model of your RV or camper. Large RVs can have surprisingly big water tanks that could take multiple minutes to fill.

In contrast, a small camper may just have a small tank that is used for a basic water supply to use for things like filling up the kettle or brushing your teeth.

Clean your freshwater Tank

When you fill the tank, it’s always worth checking if it needs cleaning.

1) Unscrew the water inlet from the faucet and drain the water from the faucet.
2) Remove the water from the inlet screen.
3) Remove the screen at the bottom of the inlet on the inlet adapter and draining the water from the screen
4) Seal the inlet screen on the top of the inlet adapter with Plumber’s putty.
5) Cut a pipe cleaner in the end of it about a half inch long
6) Place the pipe cleaner against the bottom of the screen and push down on the pipe cleaner while turning the inlet to the left to loosen the seal that was created with the curvy end of the pipe cleaner.
7) Retrieve the pipe cleaner and discard.
8) Rinse the water tanks with one gallon of hot water.
9) Use dishwasher detergent to clean out the faucet inlet.
10) Boil two cups of water to add on top of the RV freshwater tank
11) Wait about a minute for the water to permeate into the tank and check the water level in the tank.
12) Deep clean the RV freshwater tank once a year.

In order to remove the odors coming from the tank, a disinfectant, such as Bac-out, can be added to the tank water. There are different methods to deep clean the tank such as two cycles of dishwasher detergent followed by a cycle of hot water. The steps that can be used and the frequency of doing the cleaning is determined by how bad the smell is.

In case of water shortage, a couple of days can be saved by storing the shower water in buckets. The grey water tanks can then be drained into taps and used for washereyespecially to wash the dishes.