Winterizing Your RV: Part 1 – How to Winterize Your RV’s Water System

Winterizing your RV – whether it’s for a travel trailer, fifth wheel, or motorhome – can be a chore. But it’s necessary for prolonging the life of your camper and protecting your investment. In this post, we’ll cover how to winterize the plumbing in your RV.

Pro Tip: Read your owner’s manual before you get started for model-specific RV winterizing instructions. Some newer models have built-in winterizing controls, so not all steps may apply to your RV.

Winterizing your RV’s water system means removing as much liquid as possible from the pipes and adding RV anti-freeze to prevent any remaining water from becoming frozen. It’s very important to take time to winterize the water system properly because any water remaining in the pipes can freeze and cause damage if the temperature falls below freezing.

How to Winterize Your RV’s Plumbing

A man opens the drain valve on his RV to allow water to drain from the plumbing. This is the first step to winterizing your RV.
Draining your RV’s plumbing is the first step to winterizing your RV.

Drain Your RV’s Water System

To begin, drain and flush the black and gray water tanks at a dump station. Clean the black water tank with a wand attachment at the end of a hose.

Next, drain the fresh water tank. This will remove water that could potentially cause your pipes to freeze and burst, and it saves you from getting sprayed when you open the drains or unscrew the plug on your water heater. Drain all water from the system at the low point drains. Refer to your owner’s manual if you need help locating the low point drains.

Now, make sure the water heater tank has had time to cool before you attempt to drain it.With no water connected to the RV and the 12-Volt water pump in the “off” position, open a hot water faucet to relieve any pressure in the lines. Make sure the RV is not plugged into 110 volts and turn off the 110 volt electric switch to the water heater, if so equipped. Drain your water heater tank and leave the drain plug open.

This is a good time to clean the inside of the tank with a wand attachment at the end of a hose. While you’re at it, check the anode rod to make sure it’s in good condition. Replace if corroded.

A old anode rod is displayed next to a new anode rod. The old rod shows signs of rust and corrosion; it needs to be replaced.
The anode rod on the left shows corrosion and should be replaced to protect your water heater.

Open all the hot and cold water faucets and flush the toilet to help get remaining water out of the system. If your RV has an exterior sink or hose, be sure to drain that, too. Some people opt to blow compressed air into their pipes after completing the steps above to help remove more water. However, blowing compressed air into the lines may cause them to become loose, split, or burst. Be cautious and never use more than 40 psi when blowing out the lines. You can also use your RV’s water pump to help remove water from the system, but make sure to turn the pump off as soon as the lines are drained; otherwise, you’ll risk damaging the pump.

Recap the drains and close the faucets when complete.

Connect Anti-freeze to Your RV’s Water System

Now, it’s time for the second part of winterizing your RV’s water system: adding RV anti-freeze. Always be sure to use RV-specific anti-freeze and never use automotive anti-freeze in your RV’s water system.

If you have a water filter, remove it and install a filter bypass kit. This will prevent the anti-freeze from ruining the filter. You’ll also want to bypass the water heater so you don’t waste gallons of anti-freeze (the anti-freeze will fill the water heater tank before it goes through your lines). If your RV doesn’t have a water heater bypass kit, you can purchase one from your local parts store.

There are a few different ways to add anti-freeze:

  • Option one: Find the water pump and disconnect the suction side of the pump. Install a hose with fitting onto the pump, and insert the other end of the hose into a jug of RV anti-freeze.
  • Option two: Install a T-bypass valve in the water line between the fresh water tank and the pump. Run a hose from this valve into your jug of RV anti-freeze. This accomplishes the same as the first method, but without having to adjust the water pump.
  • Option three: Use an anti-freeze hand pump kit to do the same task. Drop the pump into your jug of RV anti-freeze and connect its hose into the city water inlet of your RV.
A jug of RV anti-freeze is connected to the city water intake line.
Always use RV-grade anti-freeze when winterizing your RV.

Once you’ve chosen a method and connected the anti-freeze, turn on the pump and run the anti-freeze through the lines to winterize your RV’s plumbing. We recommend starting with the highest points (shower heads) and working your way down. Start with the shower closest to the pump, and turn on the hot and cold faucets until the bright pink anti-freeze flows through the line.

Repeat this process for sinks, hoses, and toilets. Flush the toilet until anti-freeze runs through the bowl. Don’t forget to do any exterior hoses and sinks. Depending on your RV’s water system, this may take 2-3 gallons of anti-freeze. Switch out the jugs as needed.

Add Anti-freeze to Drains, Seals, and Water Heater

After pumping water through the system, pour a small cup (about 4 ounces) of anti-freeze down each drain. Pour a few ounces of anti-freeze in the toilet and flush it into the holding tank. This will prevent any remaining water from freezing.

A man pours RV anti-freeze in sink drains to winterize the RV's plumbing.
Add RV anti-freeze to sink drains when winterizing.

If you have an on-demand water heater, refer to the owners’ operation manual for specific directions on winterization procedures. Then, add RV anti-freeze to the water heater. Turn the bypass valve back to the normal position or reconnect the lines on the back of the water heater. Pump about a half-gallon of anti-freeze into the water heater. If your water heater has an electric heating element, make sure it is turned to the “off” position. This will protect the element if the RV is plugged in while in storage.

Add about an ounce of RV anti-freeze into the city water inlet to protect the check valve. Add a few ounces of RV anti-freeze to the black and gray tanks to winterize their check valves.

Last Steps

Check your owner’s manual for specific winterizing instructions for icemakers and washing machines, if applicable to your RV.

Finally, wipe down all sinks, tubs, and showers thoroughly to remove any excess anti-freeze in the basins because RV anti-freeze can stain.

Whew! Your have successfully winterized your RV’s plumbing! But, there’s more to do. Take a short break before you check out part two of our RV Winterization series. In the next post, we’ll cover a list of items to clean before your RV goes into storage.

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