Learn How to Blow Out Pool Lines for the Winter

When the season changes and the days get shorter and cooler, you will probably begin gearing up to close your pool for the winter. Closing your pool reduces the need for ongoing maintenance throughout the winter months and protects it from potential cold-weather damage. However, you can’t just throw a pool cover on it and call it a day. 

It is critical that you properly winterize your pool, which will make reopening the pool much easier next year. Remember, your pool is an investment, and learning how to maintain a pool through every season is essential for protecting your investment. 

Once you have thoroughly cleaned the pool, balanced the pool’s chemicals, and completed the rest of your pool closing routine that requires the pump, there is one important step left – you need to blow out the pool lines. Blowing out your pool lines is relatively straightforward and is something that any pool owner can do with the proper knowledge and equipment. 

So, if you want to learn how to completely maintain your pool yourself, this guide will help you understand why and how to blow out pool lines for optimal pool care. 

Do You Need to Blow Out Your Pool Lines?

Yes, blowing out your pool lines is an essential part of the winterizing process because it ensures that you have moved all of the water out of the system and the lines are dry. When water remains in the lines, it could freeze, which can cause damage to your pool’s equipment. Blowing out the pool lines helps prevent this from happening. Even warmer climates with mild winters can experience unusual temperature drops, so taking this extra precaution is always a good idea. In short, blowing out your pool lines is a fairly simple way to avoid additional hidden pool costs associated with unexpected repairs.

What’s Considered a Pool Line? 

Pool anatomy may seem complex at first, but there are actually just three main sections to your pool filtration system: the suction side, the equipment, and the pressure side. 

The Suction Side

The suction side of the pool contains the incoming lines. It suctions the pool water into the filtration system in order to begin the circulation process. Most pools have one or two skimmers that catch leaves, twigs, bugs, and other sizeable debris before they reach your filter. You will normally find the main drain located on the floor of the deep end, or lowest point, of the pool. 

It typically performs the same role as the skimmers, so dirt and debris that sink to the bottom exit here. The main drain also helps promote circulation. Finally, the suction lines are the pipes that transport the pool water from the skimmer(s) and main drain to the pump.

The Equipment 

Your pool pump and pool filter make up the filtration system. When blowing the pool lines, you will need to focus on the pump and filter valve. The pump creates a vacuum that pulls the water into the filtration system. Once the water moves through the pump, the force changes from pull to push and pushes the water to the filter. As the name implies, the filter then filters tiny debris, particles, and bacteria from the water. 

The Pressure Side

The pressure side is the side of the pool that returns the water back into the pool from the filtration system to complete the circulation process. The return lines move the pool water to the return jets from the filter. The return jets allow the filtered water to reenter the pool, and they also push the water around the pool to help it circulate. 

As you can see, these three sections work together to keep your pool water free of dirt and debris and to efficiently circulate the water, which helps the chemicals do their job efficiently. Properly blowing the lines when winterizing the pool will help prevent damage to this value system that helps keep your pool water pristine. 

What Equipment Do You Need on Hand?

To successfully blow out your pool line, you will only need to have a few items on hand. You can purchase these from a pool supply store or another retailer.

  • pool line blower 
  • 3 or 6 ft section of hose that connects to the blower
  • hose adapter that secures the hose into the skimmer 


The first step is to prepare the pool for the line-blowing process. First, you will need to lower the water level in the pool from 4-12\” below the skimmer. The amount of water you need to remove will depend on what type of pool cover you have. 

Next, drain or hand pump the water out of your skimmer(s). Then, if you have a multiport valve, set it to \”recirculate.\” Slide valves should be set to the \”filter\” position. Finally, you will need to connect the blower. 

Follow the manual\’s instructions carefully and make sure you plug the blower into a grounded extension, if not directly into an outlet. 

Blow Out the Suction Side

Once you have prepped and connected the blower, you will first blow out the suction side. The suction side includes all of your incoming lines. 

If you only have one skimmer, you will blow air from the skimmer to the pump. If you have a second skimmer, you will need to first blow from one skimmer to the pump and then from the pump to the second skimmer. Ensure that you close off the correct valve line at the pump, and blow air for a solid 2-3 minutes. 

To blow the main drain, you will need to reposition the valves first so that the main drain line is open, while the skimmer lines that have already been blown are closed off. For 3-way valves, you should loosen the knobs so that the handle turns past the stops. When blowing the main line, you see a large plume of air rise up. Allow it to blow for 10-20 seconds, and then close off the main drain line. 

Once the line is sealed properly, it holds the water back with a column of air to prevent water from entering. If you have other lines on the suction side (spa drain, cleaner line, etc.), remember to turn the valves again and send air from the skimmer through each of these lines. 

Blow Out the Equipment

Next, to protect your equipment, it is essential to drain the pump, filter, and heater. You should first remove the drain plugs on the pump, which will allow the air to push out any residual water. Loosely replace the drain plugs. 

If you have a heater, you will need to repeat this process for it as well. The multiport valve needs to be set to recirculate. If you have a slide valve, you will blow the air through it. If you do not have a slide valve on the filter, remove the filter drain plug, and again, replace it loosely when finished. 

Blow Out the Pressure Side

Once you have successfully blown air through the pump, filter, and heater, it should then be sent back to the pool by way of the return lines. You should notice bubbling from the return lines closest to the pump first. Blow for 2-3 minutes, and then plug off the return line that is bubbling the most. Next, plug the other lines tightly in a similar way, making sure no air bubbles appear. Just as with the suction side, you will need to blow additional lines, like spa return lines or automatic cleaner lines, separately. 

If you have a waterfall or fountain pump, these will generally be blown out at the pump. If there is not a tee fitting for you to connect the blower, you will just need to remove the pump lid, hold the blower hose, and blow air through in both directions. 

What Tools Should You Not Use While Blowing Out Pool Lines?

You will hear rumors or read articles about how you can use an air compressor, a shop vac, or even a leaf blower to blow pool lines. In theory, these sound like suitable alternatives. In reality, however, they are not explicitly designed for the task at hand, and you may likely run into more problems and have less successful results. 

For example, they have different air volume than pool line blowers, and even if they can blow out shallow skimmers and return lines, they often will not blow out the main drain line. So, if you want to ensure the most successful results the first time, you might as well start with the right tools. Also, remember that quality equipment gets the job done more efficiently, which will save you time and money in the long run. 

Gear Up for Next Year With the Best Pool Tools You Can Get

The best way to ensure you enjoy your pool summer after summer is to take care of it year-round. From the routine maintenance discussed in our pool maintenance guide to properly winterizing your pool at the end of the swimming season, responsible pool ownership means you have the right tools and equipment. However, if you do not know which pool tools to consider, ProTuff has you covered. We not only manufacture quality pool tools with a lifetime guarantee, but we are also here to help make pool ownership simple and enjoyable. Contact us today to learn more about ProTuff products, and subscribe to our newsletter for the latest tips and pool care.



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