RiversideTrailer is reader-supported. When you buy via our links, we may earn a commission at no cost to you. Learn more

How to Winterize Your RV Water System: 2 Easy Methods

Written by Philip Lopez / Fact checked by Paul Lemaire

how to winterize your rv

When the weather gets cold, it’s time to prepare your RV for the worst. The cold temperature will freeze your water system and cause severe damage to pipes while your camper is sitting or traveling.

Therefore, you need to know how to winterize your RV correctly.

There are two options you can look at for trailer winterization. You can either blow the water lines out with air or use antifreeze.

You’ll need an adapter for the first method and a winterize kit if you go with the antifreeze route. The cost to winterize an RV depends on the method you’ll choose.

Table of Contents

Method 1: Blowing Out The Lines

Using an air compressor may cost less than using antifreeze because you only need an adapter. The number of tasks can be tedious, though.

What To Prepare

  • Air compressor kit (if your RV comes without air compressor)
  • Adapter or blow-out plug with quick connect
  • 1 gallon of antifreeze

Step 1: Empty All Tanks


The first step in winterizing RV trailer is to clean and empty the black, gray, and freshwater tanks.

  • Disconnect the fresh water hose and drain it of all water.
  • Turn the water pump off, then discharge your black and gray tanks at a dump station. You can also hook up to your campground sewer system.
  • Once everything drains out, flush out the black and gray tanks. Consider using a cleaning wand if your RV has no flush system.
  • To drain the fresh water tank, open the low-point drain lines. Close the lines when you feel it’s empty.

Watch how to drip those low-point drains in this video.

Step 2: Drain Water Heater

The next step is to empty the water heater. This appliance is tankless, so you can’t find any water reservoir.

Before you drain the water heater, make sure that it’s not filled with hot water, or else you’re going to get yourself burned. Here’s what you should do.

  • Turn the water heater off the day before you winterize the RV.
  • Outside of your camper, remove the drain plug for your heater and open the pressure relief valve to drain all the water.
  • Once it stops draining, close the valve and return the plug to its place.

Step 3: Bypass The Water Heater And Drain Water Pump

One function of the bypass is to prevent filling the water heater with gallons of antifreeze, which is a waste. Install a kit if your RV doesn’t have a water heater bypass system yet.

Your water heater probably has a bypass with three valves whose positions you need to change. This setup will create a loop, preventing water entry into your water heater.

  • Close the two valves going and coming out of the water heater.
  • Open the valve that’s in between the two short pipes.

Besides the water heater, you also want to empty your fresh water pump. Any trace of water will freeze the pump, so you don’t want any moisture left in it.

Start the pump and turn on the faucet for 15 seconds. Please don’t do it for more than a minute because it will damage the pump.

Step 4: Blow The Water Out


First, set the pressure to a minimum, enough to move some air and blow out the water. Now, let’s start blowing some water out of the lines.

  • Connect the air compressor adapter to the trailer’s water inlet.
  • Before you hook the hose, remove any inline filters.
  • Connect the air compressor and open each water fixture inside and outside the RV.
  • Once all water drains out, close the faucets.

Don’t forget to do the hot and cold sides of the faucets, bathroom shower, toilet, outside shower, and low point drains.

Step 5: Pour antifreeze

To finish, put the antifreeze solution to the P-traps to prevent water from sitting there.

Method 2: Winterizing Motorhome With Antifreeze


If you don’t want to mess with your air compressor, you can winterize travel trailer with antifreeze. Here’s a checklist of materials and steps.

What To Prepare

  • RV winterize kit (includes a valve, hose, etc.)
  • 3-4 gallons of antifreeze
  • A helping buddy

Step 1: Install The Valve And Hose

Like in Method 1, drain the water heater and bypass it so you won’t waste several gallons of antifreeze in that large area. Don’t forget to drain the RV’s system and interior lines.

The next step to winterize RV with antifreeze is installing the valve that came with the winterize kit. Put the valve at the side of the pump and hook up the siphon hose that will suck up the pink antifreeze from the jug to the water lines.

Step 2: Start The Antifreeze

Before you winterize a camper, it would be best to have someone guard the antifreeze to check when it’s running out and needs a refill. So, let’s begin.

  • Turn on the pump and open the kitchen faucet to let the water run.
  • When the water turns pink, turn the faucet off because it indicates that the antifreeze has infiltrated.
  • Do the same with the bathroom sink, toilet, shower, outside water fixtures, and low point drains. Make sure to do both the cold and hot sides to protect them from freezing up.
  • Don’t forget the RV city water inlet. Push the button beside it to let the antifreeze pour out.
  • Once all fixtures are winterized, pour some antifreeze on the P-traps.

Furthermore, if you don’t want to use antifreeze substances, this guide is made for you!


At this point, you should know how to winterize your RV by using air or antifreeze substances. Both are effective, but using the antifreeze solution is easier. However, it may cost more as you have to buy plenty of gallons.

The key to this winterization process is draining all the water from your water tanks and pipes.

Let us know what your thoughts are about this tutorial. If you like it, please share it with your friends.

5/5 - (3 votes)