Air Compressor to Close Pool: Easy Steps for Winterizing

Closing your pool for the winter is a task that many homeowners handle themselves. Doing it right saves money, protects your investment, and gives peace of mind. But one tool often stands out in this process: the air compressor. If you have ever wondered how to use an air compressor to close your pool, or why it matters, you are not alone. Many pool owners overlook small details, which can lead to expensive repairs in spring. This guide will walk you through everything you need to know, from choosing the right compressor to step-by-step instructions, safety advice, and answers to common questions. Whether you are a new pool owner or have closed your pool for years, you will find practical tips and expert insights that go beyond the basics.

Why An Air Compressor Is Essential For Pool Closing

Winter can be tough on pools. When water freezes in pipes or equipment, it expands and can cause cracks or bursts. Draining water alone is not enough because small amounts remain in pipes and filters. This is where an air compressor comes in. It uses pressurized air to blow out any water left in the plumbing system, preventing freeze damage.

Using an air compressor is safer and more reliable than just draining by gravity or using a wet/dry shop vac. Compressors create enough force to clear even the tricky spots, like deep return lines and the bottom of the skimmer.

If you skip this step, the risk of expensive leaks, broken pipes, or damaged pumps increases. Some pool owners try to save time or money by skipping the compressor, but often regret it when spring repairs cost hundreds or even thousands of dollars.

Understanding The Pool Closing Process

Proper pool closing involves several steps, not just blowing out pipes. Here’s how the air compressor fits in the bigger picture:

• Balance water chemistry – Adjust pH, alkalinity, and calcium to recommended levels. This prevents corrosion and scaling during winter.
• Clean the pool – Remove leaves and debris. Brush and vacuum thoroughly so nothing rots under the cover.
• Lower water level – Usually below the skimmer, but not too low. Exact height depends on your pool type.
• Drain and winterize equipment – Pump, filter, heater, and chlorinator need to be drained.
• Blow out lines – Use the air compressor to push water out of all pool pipes.
• Add pool antifreeze – In very cold climates, antifreeze offers extra protection in case water remains.
• Install winter plugs and cover – Plug the returns and skimmer, then place the winter cover.

The air compressor step is crucial, and often takes the most attention to do right.

How An Air Compressor Works For Pool Closing

An air compressor takes in outside air and pushes it out at high pressure through a hose. When attached to pool plumbing, this air moves through the pipes, forcing out all water. You connect the compressor to the pump, skimmer, or a dedicated blow-out line, depending on your setup.

There are different types of compressors, but for pool closing, the most common are:

• Portable electric compressors: Easy to move, often used for tools or inflating tires.
• Shop compressors: Larger, more powerful, sometimes stationary.

The air pressure is measured in PSI (pounds per square inch). For pool lines, you usually need 10–20 PSI. Too much pressure can damage pipes or fittings, so it’s important not to overdo it.

Choosing The Right Air Compressor For Your Pool

Picking the right air compressor can make your job much easier. Here are some key features to consider:

Size And Power

• CFM (Cubic Feet per Minute): This measures how much air the compressor delivers. For most pools, a compressor with 3–5 CFM at 40 PSI is enough.
• Tank Size: Larger tanks (4–10 gallons) can blow out longer lines without stopping. Small tanks may need to refill often.

Portability

If your pool equipment is far from your garage or shed, choose a model with wheels or a carrying handle.

Power Source

• Electric: Most common for home use. Quiet, clean, and easy to run.
• Gas-powered: For large properties or places without electricity. Louder and heavier, but more powerful.

Pressure Adjustment

Look for a compressor with an adjustable regulator. This lets you set the PSI to a safe level for pool pipes.

Common Mistakes In Compressor Selection

• Overpowered units: Some people buy construction-grade compressors, which can damage PVC pipes.
• Too small: Mini tire inflators often do not have enough airflow to clear long plumbing runs.

Compressor Comparison

Here’s a comparison of three common air compressors for pool closing:

Most homeowners find a pancake or hot dog electric compressor works well.

Tools And Supplies Needed

Before you start, gather everything you need. Besides the air compressor, you should have:

• Winterizing plugs (for returns, skimmer, and cleaner lines)
• Pool antifreeze (non-toxic, if needed)
• Screwdriver or socket set (for pump and filter drain plugs)
• Teflon tape (for sealing threads)
• Garden hose (to lower water level)
• Safety glasses and ear protection (for when using the compressor)
• Adapter fitting (to connect compressor hose to pool plumbing)
• Rubber mallet (to tap in plugs if needed)
• Owner’s manual for your pool equipment

A common beginner mistake is not having the right adapter fitting. Pool stores sell universal blow-out adapters, or you can make one with parts from a hardware store.

Step-by-step Guide: Using An Air Compressor To Close A Pool

Getting the process right is important for your pool’s health. Follow these steps for a smooth, safe close.

1. Balance Your Water

Test and adjust the pool water’s pH (7.2–7.6), alkalinity (80–120 ppm), and calcium hardness (180–220 ppm). Add winter chemicals as needed, such as algaecide or a metal sequestrant. Run the pump for at least 24 hours after adding.

2. Clean The Pool

Remove all leaves, brush walls, and vacuum the bottom. Even small debris can stain or cause problems over the winter.

3. Lower The Water Level

Use a submersible pump or siphon hose to bring the water below the skimmer opening, but above the bottom of the return jets. For vinyl pools, do not lower too much—exposed liners can shrink or tear.

4. Drain Equipment

Shut off the pump. Open drain plugs on the pump, filter, heater, and chlorinator. Let water drain out completely. Remove any pressure gauges or glass sight tubes.

5. Connect The Air Compressor

• Attach your adapter fitting to the pump’s drain plug or skimmer opening.
• Connect the air compressor hose to the adapter.
• Make sure all return and suction lines are open (not plugged yet).
• Set the compressor pressure to 10–20 PSI.

6. Blow Out The Lines

• Turn on the compressor.
• Watch for water and air bubbles at each return jet, skimmer, and main drain.
• When only air comes out, insert a winterizing plug while the compressor is running.
• For the skimmer, put in a Gizzmo or similar plug.
• For the main drain, keep blowing until you see air bubbles at the drain cover in the pool. Then quickly close the valve to trap air in the line.
• Repeat for all lines.

If you have a pool cleaner line, blow it out last. Some pools have unique features—check your manual for details.

7. Add Pool Antifreeze (if Needed)

Pour non-toxic pool antifreeze into lines that might hold water, especially in very cold climates. This is extra insurance in case some water remains.

8. Plug And Seal Everything

Check all lines are plugged tightly. Use Teflon tape if needed for a tight seal. Remove the compressor and adapter.

9. Cover And Secure The Pool

Install your winter cover, securing with water bags, weights, or cables as needed.

Credit: ghurairproperties.com

Special Tips For Different Pool Types

Inground Pools

Most inground pools have several returns, a skimmer, and a main drain. The main drain is the trickiest—many people do not blow it out long enough. Wait for steady bubbles at the pool drain cover before closing the valve.

Above Ground Pools

These pools usually have fewer lines and no main drain. Lower the water below return jets, then blow out both the return and skimmer lines. Some above ground pools have hoses that can be disconnected instead.

Saltwater Pools

Salt can leave deposits in plumbing. After blowing out the lines, consider flushing with fresh water and blowing them out again. Remove salt cell and store indoors if possible.

Common Mistakes And How To Avoid Them

Many beginners make small errors when using an air compressor to close a pool. Here are the most frequent ones, and how to avoid them:

• Setting the pressure too high – More is not better. Use only 10–20 PSI to avoid damaging pipes.
• Not blowing out long enough – It can take 1–2 minutes per line. Wait until you see only air, no water.
• Forgetting to open all valves – If a valve is closed, trapped water can freeze and break the pipe.
• Not plugging lines while air is flowing – Plug each line quickly after water stops, while air is still coming out.
• Missing hidden lines – Some pools have cleaner or fountain lines. Double-check your pool’s layout.
• Using the wrong antifreeze – Never use automotive antifreeze. Only non-toxic pool antifreeze is safe.
• Leaving the compressor unattended – Always watch the process. Over-pressurizing can cause accidents.

These mistakes can be costly, but are easy to avoid with careful planning.

How To Make An Adapter For Your Air Compressor

Many pool owners struggle to connect the compressor hose to their pool system. You can buy a special blow-out adapter, or make one yourself with common hardware parts.

You need:

• A 1.5” threaded male adapter (fits the pump drain port or skimmer)
• A tire valve stem (from an auto parts store)
• Hose clamps and Teflon tape

Drill a hole in the adapter, insert the valve stem, and seal with Teflon tape. This lets you attach the compressor as you would inflate a tire.

Comparing Shop Vac Vs. Air Compressor

Some people use a wet/dry shop vac to blow out pool lines. This can work on small pools or short lines, but has drawbacks.

Air compressors are more reliable for clearing all water, especially in complex or larger pools.

Safety Tips When Using An Air Compressor

Safety should never be an afterthought. Here’s how to protect yourself and your pool:

• Wear safety glasses and hearing protection – Compressed air can blow debris or water back toward you.
• Never exceed 20 PSI – Higher pressures can burst PVC pipes or fittings.
• Keep children and pets away – The noise can be startling, and air/water can spray unexpectedly.
• Check hoses and connections – Loose fittings can pop off under pressure.
• Release pressure slowly – After finishing, bleed the compressor hose before disconnecting.
• Don’t inhale air from the compressor – It may contain oil or particles.

Some new pool owners forget that compressors are powerful tools. Used properly, they are safe, but caution is always best.

Practical Troubleshooting: What If Something Goes Wrong?

Even with careful planning, problems can happen. Here’s what to do if you run into issues:

Air Not Coming Out The Returns

• Check that all valves are open.
• Confirm the adapter is sealed tightly.
• Make sure the compressor is running and set to the correct PSI.

Water Keeps Dripping After Blowing Out

• Some water can remain in low spots. Try raising that section of pipe if possible.
• Use pool antifreeze as a backup.

Main Drain Does Not Bubble

• Blow out for 1–2 minutes. If still no bubbles, check for a closed valve or blockage.
• Some pools have a hydrostatic valve at the drain that may not allow air to escape.

Plug Pops Out

• Air pressure may be too high. Lower the PSI and try again.
• Make sure the plug is the right size and seated firmly.

Compressor Overheats Or Trips Breaker

• Too small a compressor may overwork. Allow it to cool, or upgrade to a larger model.

Most problems are simple to fix. If you are unsure, it is better to call a pool professional than risk damage.

Environmental And Cost Benefits

Using an air compressor for pool closing is not just about safety. It also has environmental and financial benefits:

• Reduces water waste – You do not need to drain the pool completely.
• Minimizes chemical use – Balancing chemicals before closing means less to add in spring.
• Lowers repair costs – Prevents expensive freeze damage.
• Saves time – Compressors are faster and more thorough than manual methods.

According to the Association of Pool & Spa Professionals, homeowners who winterize their pool with a compressor spend 40–60% less on spring repairs compared to those who skip this step.

Real-world Example: Closing A Medium Inground Pool

Let’s look at a practical example. John has a 16×32 foot inground pool with two returns, one skimmer, and a main drain.

• He uses a 6-gallon, 3.5 CFM pancake compressor.
• Lowers water below skimmer, drains pump and filter.
• Connects compressor with an adapter to the pump drain.
• Blows out each line for about 90 seconds, watching for water and then air.
• Plugs returns and skimmer while air is flowing.
• Adds 1 gallon of pool antifreeze to each line as backup.
• Covers the pool with a safety cover.

This takes about 2 hours. In spring, he finds no cracks, leaks, or algae, saving $500+ in repairs compared to a neighbor who did not blow out lines.

Credit: www.youtube.com

Professional Vs. Diy: When To Hire A Pool Service

Some pool owners prefer to hire a pro. Here’s how to decide:

Diy Is Best If:

• You are comfortable with tools and following instructions.
• You have a simple pool design.
• You want to save money ($150–$300 per closing).

Hire A Pro If:

• Your pool has complex plumbing or features.
• You lack the right compressor or tools.
• You are unsure about any step.

Even if you usually do it yourself, calling a professional every few years is a smart way to check for hidden problems.

Maintenance Tips For Your Air Compressor

To keep your compressor working year after year:

• Drain the tank after each use – Water can collect and cause rust.
• Check oil level (if required).
• Inspect hoses and fittings for cracks or wear.
• Store indoors to protect from weather.
• Run the compressor every few months to keep seals lubricated.

A well-maintained compressor lasts for many seasons.

How To Store Your Pool After Blowing Out Lines

Once you finish with the air compressor:

• Store all plugs and adapters in a labeled bag.
• Keep your compressor in a dry, clean spot.
• Check the pool cover every month for damage or debris.

Proper storage helps you open the pool quickly in spring.

Where To Learn More

For those who want more technical details or visual guides, the National Swimming Pool Foundation and SwimmingPool.com offer further reading and videos. These resources give more in-depth info on pool types and equipment.

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Frequently Asked Questions

How Much Psi Should I Use When Blowing Out Pool Lines?

Use 10–20 PSI. More pressure can damage pipes or fittings. Always start low and increase slowly if needed.

Can I Use A Shop Vac Instead Of An Air Compressor?

A shop vac can work for short lines or above ground pools, but usually does not create enough pressure for long or complex plumbing. An air compressor is more reliable for complete winterization.

Do I Need To Add Pool Antifreeze After Blowing Out The Lines?

Pool antifreeze is recommended in very cold climates or if you are not sure all water is removed. It is extra insurance. Use only non-toxic antifreeze made for pools.

What Size Air Compressor Is Best For Closing A Pool?

A compressor with 3–5 CFM at 40 PSI and a 4–8 gallon tank works for most home pools. Portable electric models are the most popular.

Is It Safe To Close My Pool Myself?

Yes, if you follow instructions, use the right tools, and do not rush. If you are unsure, it is always smart to get help from a pool professional.

Closing your pool with an air compressor is one of the most important steps to protect your investment. With the right tools, a bit of patience, and attention to detail, you can avoid costly winter damage and enjoy a trouble-free opening next spring.