How to Blow Out Pool Lines For Your Winter Closeout

19,Sep 2022

With fall approaching quickly, it’s time to prepare your pool for the end of the season. One major step you need to take when closing your pool is to blow out the pool lines so they are winterized.

At Swimming Pool Discounters, we’ve put together a guide on how to blow out your pool lines. With these instructions and the right equipment, you can easily complete this pool closing task.

Pool Plumbing Winterization Questions

At Swimming Pool Discounters, we get many questions from customers about pool plumbing winterization, including:

Will an air compressor blow out the pool lines?

You can certainly use an air compressor to blow out your pool lines. However, there is a chance that you could over-pressurize your piping and fittings. When you use an air compressor, you are using high air pressure and low airflow. On the other hand, when you use a pool line blower, you get a low and consistent air pressure and more air volume.

Would a leaf blower work for pool piping winterization?

While you think this may work, even the higher-power gas leaf blowers have little success in blowing out the pool pipes. You may be able to utilize a leaf blower for the shallow skimmer or return lines once that water level is lowered.

Can I use a Shop Vac to blow out my pool lines?

It is possible. We recommend using a large canister-type Shop Vac that has five horsepower or more to handle the water resistance. With some wet/dry vacs, you may be able to blow out the skimmers and return lines, but most won’t blow out the main drain line.

The Right Solution: Pool Line Blower

We highly recommend using a pool line blower that offers the right pressure and power to properly blow out your pool lines. With a pool line blower, you won’t need to lower the water level to blow out the main lines. Blowing out the small lines, large lines, and deep lines is also a breeze. Another great thing about pool line blowers is that they are portable, durable, and user-friendly.

How to Prepare to Blow Out the Pool Lines

First, lower the pool water level by 4 to 12 inches below the skimmer, based on your pool cover type. You then need to remove the pump, filter, and heater drain plugs and then replace them loosely.

Remove the water from the skimmer by hand pumping, draining, or scooping the water until it is almost empty. Set your multiport valve to recirculate or to the filter position if you have a side valve.

Once these steps are completed, it’s time to attach the pool line blower. You will use a 3ft or 6ft section of hose to connect the pool line blower along with an adapter to secure the hose into the bottom of the skimmer.

Once you’ve attached the hose to the bottom of the skimmer, thread the hose adapter into the other end of the blower. You will then need to plug the blower into your grounded extension cord or into an outlet.

Steps for Blowing Out the Pool Lines

Start by blowing out the suction side, then blow out the equipment, and then blow out the pressure side. We’ve detailed this process below:

Suction Side

The suction side is considered to be all of the incoming lines. In most cases, a pool will have one or two skimmers along with the main drain line on the suction side of the pump. These pipes come together and come into the pipe.

For those with a second skimmer, you can blow air from one skimmer to the other. To do this, you need to close off the valve at the pump or take off the pump lid and plug the port that comes into the pump.

Using a second hose, or vacuum hose, you can connect to your second skimmer to prevent reaching into the skimmer and plugging it while it is spraying. We recommend blowing air through the skimmer lines until a mist is blowing out.

To blow out the main line, you will need to re-position the valve to blow air through the main drain. Watch for a major plume of air to rise from the drain and allow this to blow out for about 10 seconds, closing off the positively sealing valve on your main drain line to hold back the column of air.


Once the above steps on completed, you will need to blow air through the pump and the filter valve. To do this, remove the drain plugs that are on the pump and allow the air to blow any remaining water out. Loosley, replace your drain plugs, and if you have a heater, do the same.

For the multiport valve, set the handle to recirculate, and for the slide valve, the air will go through the filer. Remove the drain plug from your filter and replace it loosely if water is blowing their the filter. If you leave the filter cartridges inside the tank, check that the tank clamp band is tight before the water pressurizes the tank.

Pressure Side

We now need to send the air back to the pool through the return lines. You will begin to blow out the return lines that are closest to the pump. Once they have been blowing for two to three minutes, be sure to plug the wall return that is bubbling the most. You will then need to plug the other return lines. Be sure to make a tight seal with the pool plugs, turning the wingnut until the air bubble cease.

Contact Swimming Pool Discounters today for all of your pool winterization needs!