If you're getting ready for winter, blowing out pool lines with air compressor is one of the most important tasks you'll tackle to avoid cracked pipes and expensive repairs. Honestly, nobody wants to deal with a frozen, burst pipe buried three feet underground when spring rolls around. It's a total nightmare that can cost thousands to fix. Fortunately, if you have a decent air compressor and a bit of patience, you can handle this job yourself without paying a pool company hundreds of dollars to do the exact same thing.
Why you should do this yourself
Let's be real: pool maintenance is expensive. Between the chemicals, the electricity for the pump, and the occasional equipment fail, the costs add up fast. Winterizing is just another one of those chores that feels like a huge burden. But here's the thing—it's actually pretty straightforward. Once you understand the basic physics of pushing air through water-filled pipes, it becomes a lot less intimidating.
Using an air compressor is the most effective way to ensure there's no standing water left in the plumbing. While some people try to use a shop vac, those usually don't have the "omph" needed to push water through deep lines or complicated heater setups. An air compressor gives you that steady, pressurized flow that gets the job done right.
Getting the right gear ready
Before you go out and start sticking hoses into your pool equipment, you need to make sure your compressor is actually up to the task. You don't need a massive industrial unit, but a tiny tire inflator isn't going to cut it either. You're looking for something that can provide a decent volume of air (CFM) rather than just high pressure (PSI). In fact, high pressure is actually your enemy here—you don't want to blow your pipes apart.
Aside from the compressor, you're going to need a specific adapter. This is usually a plug that screws into your pump's drain port or a specialized blow-out plug that fits into your skimmer. You can find these at most pool supply stores or online. It basically bridges the gap between your air hose and your pool's plumbing. Grab some Teflon tape too, just to make sure the seal is tight.
Preparing the pool for the blowout
You can't just start blowing air while the system is full and running. First, you need to turn off all the power to your pool equipment. Safety first—don't skip this. Once the power is off, you'll want to lower the water level in the pool. Most people drop it just below the skimmer mouth.
Next, head over to your filter and pump. Open the air relief valve on top of the filter to let the pressure out, then remove the drain plugs from the pump, the filter, and the heater. Let all that water drain out onto the equipment pad. If you have a chlorinator or a salt cell, now is a good time to drain those too. It's a lot of little steps, but skipping one could mean a cracked housing later on.
Setting up the air compressor
Now it's time to hook things up. Take your air compressor and set the regulator. This is the most critical part: do not exceed 10-15 PSI. You might think more pressure means a faster job, but pool PVC isn't designed to handle massive blasts of air pressure from a compressor. It's designed for water flow. Keep it low and steady.
Attach your adapter to the pump's drain plug opening or the basket housing. If your compressor has a small tank, let it fill up completely before you start. You want a consistent stream of air, not a series of short bursts. Once everything is snug, you're ready to start the actual "blow out" part of the process.
Clearing the skimmer lines first
Usually, it's best to start with the lines closest to the pump, which are typically the skimmers. If you have a multiport valve, set it to "Recirculate" to bypass the filter. This makes the air's path a lot easier.
Turn on the compressor and wait. After a few seconds, you should hear a bubbling sound coming from the skimmer. Eventually, that bubbling will turn into a massive spray of water as the air pushes everything out. Once it's just air coming out of the skimmer, it's "dry." At this point, you'll want to shove a rubber expansion plug into the hole at the bottom of the skimmer to seal it off. Some people like to add a "Gizzmo"—that long plastic tube thing—which helps absorb any pressure if ice happens to form later.
Moving on to the return lines
After the skimmers are done, it's time to tackle the return lines—those are the jets where water normally flows back into the pool. This part can be a little like playing Whac-A-Mole. Since air takes the path of least resistance, it's going to want to come out of the jet closest to the pump first.
Let the air blow through the first jet until it's mostly mist and air, then plug it with a winterizing plug. Once that one is plugged, the air pressure will move down the line to the next jet. Repeat the process until every single return line is bubbling air and then plugged tightly. If you have a dedicated vacuum line or a pressure-side cleaner line (like for a Polaris), don't forget to blow those out too.
Dealing with the main drain
The main drain is the one at the very bottom of the deep end, and it's the one that stresses people out the most. Since it's so deep, you're fighting a lot of water weight. You probably won't be able to "plug" the main drain unless you're a diver, but that's okay.
The trick here is to create an "air lock." Blow air toward the main drain until you see big bubbles surfacing in the middle of the pool. Let it bubble for about 30 seconds to a minute to ensure the line is as clear as possible. Then, quickly close the valve at the equipment pad that leads to the main drain. This traps a column of air in the pipe. Because air is lighter than water, the water can't push its way back up into the pipe far enough to cause freezing damage. It's a bit of pool magic that works every time.
Final checks and adding antifreeze
Once all the lines are plugged and the main drain is locked, you're technically done with the air part. But, for extra peace of mind, many people like to add non-toxic pool antifreeze to the lines. Never use automotive antifreeze—it's extremely toxic and will ruin your pool water.
Pour the pink pool antifreeze into the skimmer lines before you put the final plugs in, or use a funnel to get it into the lines at the equipment pad. This is just a safety net. If a little bit of water manages to seep back in or if you didn't get every single drop out, the antifreeze prevents it from turning into a solid block of ice that could crack the PVC.
Wrapping things up
Don't forget to put your pump and filter drain plugs in a safe spot. I usually keep mine in the pump basket so I know exactly where they are when spring arrives. Cover your equipment with a heavy-duty tarp or a specialized cover if you live in a place with really harsh winters.
Blowing out pool lines with air compressor might take an hour or two of your Saturday, but the satisfaction of knowing your pool is safe is worth it. Plus, you saved yourself a few hundred bucks. Just remember to keep that pressure low, go one line at a time, and double-check your plugs. It's one of those DIY wins that makes you feel like a pro homeowner. Now, go grab a drink and enjoy the fact that you won't be dealing with any burst pipes come April!