Ok, let’s talk about RV plumbing. It’s a pretty straight forward concept so let’s dive right in.


RV plumbing more or less consists of three different tanks that hold liquid; the fresh water tank, gray water tank, and black water tank.

Fresh Water

This is exactly as it sounds. This is your good, clean, drinkable water. When you turn on your kitchen faucet, or take a shower, you’re getting water from the fresh water tank.

How does fresh water get in?

There are two ways you can get your fresh water. One is to simply fill up your tank. There’s a valve on your rig that attaches to what is basically a garden hose. The other end of that garden hose goes to a water faucet on the outside of your house, or similar. You then have a pump that’ll send water from your tank to your kitchen faucet, shower, toilet, etc.

The other option is to bypass your tank completely and only draw from the hose. This is what you’ll be doing when you’re hooked up to a campground’s water supply or chilling in a friend’s driveway.

Can I have a hot shower?

Yes, but it’s going to be a quick one. More than likely, you’ll have a small propane water heater that warms the water for your shower. Think 6 – 10 gallons (one or two Home Depot buckets). Once it’s spent, you’ll need to wait 15 to 20 minutes before it’s filled back up with more warm water.

Gray Water

This part of the plumbing is for your fresh water after it is not fresh anymore. Your sink and shower drain into the gray water tank, and sits there until you empty it. If you’re hooked up at a campground, you can have it drain immediately instead of filling up the tank.

Black Water

This is where your toilet drains. Yep, poo goes into this tank, too. Every so often, you get the joyous experience of hooking a hose up to this tank and draining it. You’ll want to get yourself special toilet paper that breaks down easily (so you don’t clog things). This water should be treated with chemicals to reduce smell and help keep things flowing nicely when it comes time to drain.

What about feminine products?

Get your self a little waste bin with a lid, you don’t want that stuff going down your RV’s toilet.


Most rigs will have a propane system for the following:

  • Your furnace (heat)
  • Your fridge (unless you have a residential fridge that runs off electricity)
  • Your water heater
  • Some on board generators will run off propane
Where do I fill up my propane?

Most U-Haul stores and truck stops can fill you up.