Blowing Out RV Water Lines vs Antifreeze: RV Winterization Options

As winter approaches, RV owners must take measures to protect their vehicles from the harsh cold temperatures. One crucial aspect of winterizing an RV is ensuring that the water lines are properly drained to prevent freezing and potential damage. There are two primary methods for winterizing RV water lines: blowing them out and using antifreeze. Each method has its pros and cons, and in this comprehensive guide, we will explore both approaches in detail to help you make an informed decision for your RV.

1. Understanding the Importance of Winterizing RV Water Lines

Before delving into the two methods, let’s briefly discuss why winterizing RV water lines is so critical. Freezing temperatures can cause water inside the pipes to expand, leading to cracks and leaks. These damages can be expensive to repair and may result in significant inconveniences during your next camping season. Proper winterization will save you time, money, and potential headaches down the road.

2. Blowing Out RV Water Lines: The Process

Blowing out RV water lines involves using compressed air to remove any residual water from the pipes and faucets. It is essential to execute this method correctly to ensure all the water is expelled thoroughly. Here’s a step-by-step guide on how to do it:

Step 1: Gather the Necessary Tools

For this method, you will need an air compressor with an air pressure regulator, a blowout plug or fitting, and appropriate safety gear, such as eye protection and earplugs.

Step 2: Turn Off Water Heater and Water Pump

Before starting the process, switch off the water heater and water pump to prevent damage when there’s no water in the system.

Step 3: Open All Faucets and Drains

Next, open all faucets, including hot and cold taps, in the RV, as well as low point drains and the exterior shower if your RV has one.

Step 4: Connect the Compressor

Connect the air compressor to the RV’s water inlet using the blowout plug or fitting. Set the air compressor’s pressure regulator to a safe and suitable level, typically between 30 to 50 psi. Too much pressure can damage the water lines, so ensure you don’t exceed the recommended limit.

Step 5: Blow Out the Water Lines

With the compressor set up and all faucets open, turn on the air compressor. Starting from the farthest faucet, work your way towards the nearest one, allowing compressed air to push out the water from each line. Do this for both hot and cold lines until only air comes out of the faucets.

Step 6: Drain the Water Tanks

Don’t forget to drain all the RV’s water tanks, including the fresh water, gray water, and black water tanks, following the manufacturer’s instructions.

3. Pros and Cons of Blowing Out RV Water Lines

As with any RV winterization method, blowing out water lines has its advantages and drawbacks:


  • No need for antifreeze, which means no flushing of the system in spring.
  • Environmentally friendly as no chemicals are used.
  • Less expensive than buying antifreeze.


  • If not done correctly, residual water may remain, leading to potential damage.
  • Compressed air can be harmful if not used properly, risking damage to the water lines or other RV components.
  • Some RVs have intricate plumbing systems that are challenging to completely clear with this method.

4. Using Antifreeze: The Process

The second method of winterizing RV water lines involves using antifreeze, a specially formulated RV antifreeze that is non-toxic and safe for plumbing systems. This method ensures that water lines remain protected from freezing temperatures. Here’s how to use antifreeze to winterize your RV:

Step 1: Gather the Necessary Tools

To use antifreeze, you’ll need RV antifreeze (not automotive antifreeze), a hand pump or a water pump converter kit, and safety gear.

Step 2: Turn Off Water Heater and Bypass Valve

Similar to the blowing out method, turn off the water heater and bypass valve to avoid damaging them during the winterization process.

Step 3: Drain Water Tanks and Open All Faucets

Drain all the water tanks and open all the faucets, just as you would in the blowing out method.

Step 4: Insert Antifreeze into the System

Using the hand pump or water pump converter kit, insert the RV antifreeze into the RV’s water system. Start with the fresh water tank and pump the antifreeze through all the lines, faucets, and drains until you see the colored antifreeze coming out of each faucet and fixture.

Step 5: Add Antifreeze to P-Traps and Toilet Bowl

Make sure to pour antifreeze down each sink and shower drain to protect the P-traps. Also, add some antifreeze to the toilet bowl to prevent freezing.

5. Pros and Cons of Using Antifreeze

Using antifreeze as your winterization method also has its own set of advantages and disadvantages:


  • Provides a more reliable and thorough protection against freezing, as antifreeze stays in the lines.
  • Suitable for all RVs, including those with intricate plumbing systems.
  • Prevents potential damage from residual water left in the pipes.


  • Requires flushing out the system in spring to remove the antifreeze before using the RV’s water again.
  • The cost of antifreeze can add up, especially for large RVs with many water lines.
  • Some individuals may prefer not to use chemicals, even though RV antifreeze is non-toxic.

6. Choosing the Right Method for Your RV

When deciding between blowing out RV water lines and using antifreeze, several factors should be taken into consideration:

RV Type and Plumbing Complexity:

If your RV has a simple plumbing system and you are confident in your ability to blow out all the water thoroughly, the blowing out method might be sufficient.

For RVs with more complex plumbing, using antifreeze provides better assurance that all lines are protected.

Personal Preferences:

If you prefer an eco-friendly approach and don’t want to deal with flushing the system in the spring, blowing out might be the better choice.

On the other hand, if you want maximum protection and peace of mind, using antifreeze may be worth the extra effort.

Climate and Usage Frequency:

Consider how severe your winters are and how frequently you use your RV during colder months. If your RV remains unused for long periods in freezing temperatures, antifreeze might be the safer option.

7. Additional Tips for Effective Winterization

Whichever method you select for winterizing your RV water lines, there are some general tips that apply to both approaches to ensure the process is effective:

Read the Manufacturer’s Manual:

Always refer to your RV’s owner’s manual for specific instructions on winterization. Different RV models may have unique plumbing configurations or requirements.

Protect Exterior Components:

Don’t forget to winterize external showers, outdoor faucets, and any other components with water connections. Follow the same method (blowing out or using antifreeze) to protect these external elements.

Check for Leaks:

Before starting the winterization process, inspect your RV’s water lines for any leaks or damages. Fix any issues you find before proceeding with the winterization.

Dispose of Antifreeze Properly:

If you choose to use antifreeze, ensure you dispose of any excess antifreeze properly. Many areas have specific guidelines for disposing of RV antifreeze, as it is considered hazardous waste.

Inspect Seals and Gaskets:

As part of your winterization routine, check the seals and gaskets around windows, doors, and roof vents. Replace any damaged seals to prevent cold air from entering the RV.

Insulate Your RV:

Consider adding insulation to vulnerable areas, such as pipes located near the exterior walls or under the floor. Insulation can help maintain a more stable internal temperature.

Store in a Safe Place:

If possible, store your RV in a protected area, such as a covered storage facility or a garage. Sheltering your RV from the elements will reduce the exposure to extreme weather conditions.

Regular Maintenance:

Make winterization part of your regular RV maintenance routine. Proper care and upkeep throughout the year will ensure your RV is in good shape when it’s time to hit the road again.

8. When to De-Winterize Your RV

When the cold season passes, and you’re ready to take your RV out on the road again, it’s essential to de-winterize it properly. Here’s how to do it:

Flushing Out Antifreeze:

If you used antifreeze, flush out the entire water system by running fresh water through all the faucets and fixtures until the antifreeze is entirely expelled.

Reconnecting Water Lines:

Reconnect any disconnected water lines, and ensure all valves and faucets are back in their proper positions.

Fill the Fresh Water Tank:

Fill the fresh water tank and check for any leaks or issues. Turn on the water pump to pressurize the system.

Test Water Lines:

Open all the faucets one by one and check for water flow. If you used the blowing out method, pay extra attention to ensure all water lines are free from obstructions.

Check Appliances:

Test all water-using appliances, such as the water heater, toilets, and showers, to ensure they are functioning correctly.


Properly winterizing your RV’s water lines is crucial to avoid costly damages caused by freezing temperatures. Both blowing out the water lines and using antifreeze are viable methods for winterization, each with its own pros and cons. The decision ultimately depends on your RV’s plumbing complexity, personal preferences, and the climate and frequency of use.

Regardless of the method you choose, always follow the manufacturer’s guidelines and take the necessary safety precautions to protect your RV and ensure a hassle-free camping experience come springtime

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