How to Blow out RV Water Lines for Winterization

Before the temperature starts dropping, you probably want your RV to be ready for winter and save that costly damage at your disposal. Therefore, you might be looking for a simple answer on how to blow out RV water lines, right? Well, you can take your RV to a repair shop to let the expert handle it but let me tell you that it is a simple process that can be done effortlessly in your home, saving the cost of repairing, transport, and also getting your quite some time for a rest from that hard work.

Here in this article, we are going to help you in blowing RV liquid lines to winterize the motorhome and get that RV ready for winter. So, without any further ado, let us hop into the details.

How to Blow out RV Water Lines?

Looking for the best way to blow out RV water lines? The most comfortable, safest, and yet result-producing method is through an air compressor. In this method, the air is blown through the lines at exceptionally high air pressure. This makes sure that there is no liquid left in your line, completely evaporating and moving any vapors left behind.

When the temperature starts going down and at freezing points, there won’t be any vapors left behind to cause cracking and bursting of pipes. That being said in a really easy way, there are various steps that you should follow along with safety measures during the whole process.

Step-by-Step guide on How to Blow Out RV Water Lines

  • First of all, disconnect the electricity and gas from the heater of your RV water setup.
  • Drain the toilets and open all the home faucets
  • Then, drain the tanks holding liquid behind
  • Disconnect all the house liquid filtration systems brought aftermarket
  • The blowout plug should be screwed in the inlet present outside
  • To blowout, the plug, attach an air compressor
  • Set it to the optimum pressure setting
  • Turn the compressor ON
  • One-by-One open the valves to drain liquid lines
  • Slowly turn the air compressor OFF
  • Disconnect Blowout plug
  • After adding the RV anti-freeze, Finish the winterizing

Steps for Blowing our RV Water Lines

Here are some of the steps that will probably be useful for you;

Safety First

When it comes to RV maintenance, the first thing that you should note is safety. Before doing anything in the process of How to Blow out RV water lines, you need to disconnect the gas and electricity connected to the liquid heater for a minimum of 24 hours before doing the blowing.

If it is not taken care of, there are high chances you can get burns or can damage the other RV components. In case it takes too long, you can open the hot water faucets and allow them to cool.

Draining the Tanks and Unplugging the Connections

The prep work is always required before connecting the air compressor. The first step here should be draining the three RV holding tanks, including the black, fresh, and greywater. Then, connect a sewer hose to let the liquid be dumped outside.

In other cases, where you have a filtration system connected to your RV water system, then you also need to disconnect it. Make sure to remove any leftover liquid inside the heater.

Locating the Blowout Plug and Connecting Air Compressor

You might be wondering, what is this blowout plug mentioned here? Well, it is a type of accessory that holds the importance of connecting the inlet to either the storage compartment underneath or to the side of the right.

Inlet can be found with also the label “City Water” and you can find the Blowout plug as being made of plastic and in other cases stainless steel. Without a blowout plug, if you are blowing out water lines with air compressor, it can result in pipe damage, so it becomes important to connect the RV exterior intake before hooking the air compressor.

After all of this is done, you need to connect the Blowout Plug and Air compressor. The only thing you need to keep in mind is the PSI on the compressor should be between 40 and 30. In this way, there won’t be any damage because of air pressure.

Blowing the RV Water Lines and Disconnecting the Compressor

Now it’s time to get going with the real business! Slowly open the valves each at a time till it is completely blown out. Most of the present RVs have two pipes, one for the cold and the other one for the hot water, but some might even have a separate one for the heaters.

After you are done with the work, you need to disconnect the blowout plug and compressor but first, make sure to remove the blowout plug. Keep them in a safe location because of small accessories.

Bypassing Water Heater

Many of the heaters meant for RV water have around a capacity of six gallons at a time, but you don’t have to pass antifreeze through these heater pipes. So, before going to the antifreeze addition, installing the bypass line is essential for reducing the antifreeze amount being used.

Adding the Antifreeze

Adding the Antifreeze

Finally, we are at the near end, which is adding that Antifreeze to your pipes. But before we proceed to the point, you might be looking for an explanation of what is Antifreeze. It is a solution having a lower freezing point in comparison to a simple liquid. So, it becomes a safety measure to ensure that your pipes don’t crack or break.

Going a step forward, it is nearly impossible to completely blow out the liquid in pipelines, and adding that antifreeze will make sure that the remaining liquid going is at the lower freezing point for the protection of pipes.

Proceeding to the main point, before adding the anti-freeze, close the outlets to the RV holding tanks and add around one to three gallons of this solution. Most people avoid direct addition and use a handpump to add the antifreeze.

Turning On the RV Water Pump and Getting Finished

After all this, you simply have to turn the RV liquid pump but only for a few minutes. This is done to pull the antifreeze solution through the pipes. You will also see the Antifreeze flowing into the bowl after RV toilet flushing. At this moment you simply had done the whole How to Blow out RV Water Lines process yourself.

Why Blowing out RV Water Lines?

There are always a few drops of liquid left in the pipes, valves, and faucet, resulting in freezing and expansion of RV lines, that will ultimately slip apart. So, you will have to repair an exceptionally expensive motorhome. So, it is best to keep it safe and under a favored humidity, that is why winterizing is done to save you from larger expenses. 


Having a bit of confidence in yourself, you can save quite a lot of expenses along with your precious time. For this reason, we have here an incredible article on How to Blow out RV Water Lines to make the steps seamless and efficiently define everything for you to figure out effortlessly. Maintaining the liquid pipes throughout the winter season can only be done by blowing out the moisture from the pipes and RV system. So, following the step-by-step guidance provided in the article you can simply do the whole process yourself, without any outside help. 

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