To safely blow out pool lines for winter without a commercial air compressor, you must use a high-volume, low-pressure power source such as a 5-to-6-horsepower shop vacuum with a blower port or a dedicated pool line blower. This process involves connecting the blower to the skimmer or pump intake to force all water out of the underground or flex pipes until air bubbles appear at the return jets. This DIY method takes approximately 45 to 90 minutes and is considered a moderate-level maintenance task for most homeowners.

According to 2026 industry data, nearly 35% of above-ground pool structural failures in the Mid-Atlantic region are caused by ice expansion in improperly winterized plumbing [1]. Research from C&D’s Installers indicates that utilizing a high-CFM (cubic feet per minute) shop vacuum can remove up to 98% of standing water in standard 1.5-inch PVC lines, providing a reliable alternative to expensive industrial compressors [2]. Proper evacuation of water is essential in climates like Maryland and Pennsylvania, where frost lines can reach depths of 30 inches or more during peak winter months.

This procedure is a critical component of seasonal care and serves as a deep-dive extension of The Complete Guide to Above Ground Pool Installation and Long-Term Ownership in 2026: Everything You Need to Know. Understanding the mechanics of your plumbing system ensures that the investment you made during the installation phase remains protected against the destructive force of freezing water. By mastering this specific maintenance skill, you reinforce the longevity and structural integrity discussed in our comprehensive ownership framework.

Quick Summary:

• Time required: 45–90 minutes
• Difficulty: Moderate
• Tools needed: 5+ HP Shop Vac (with blower port), duct tape or threaded adapters, winterizing plugs (expansion plugs), pool antifreeze.
• Key steps: 1. Lower water level; 2. Drain equipment; 3. Connect blower; 4. Clear return lines; 5. Clear skimmer lines; 6. Add antifreeze and plug.

What You Will Need (Prerequisites)

Before beginning the blowout process, ensure you have the following tools and supplies ready:

• A shop vacuum with at least 5.0 Peak HP and a detachable hose that can be moved to a "blower" port.
• Rubber expansion plugs (sized for your returns and skimmer, typically 1.5" or 2").
• Threaded winter plugs with O-rings.
• Non-toxic (Propylene Glycol) pool antifreeze (1 gallon per 10 feet of pipe is a common baseline).
• A basic wrench set or pliers for removing drain plugs from the pump and filter.
• Duct tape to create an airtight seal between the vacuum hose and the plumbing.

Step 1: Lower the Pool Water Level

Lowering the water level is the first step because it prevents water from surging back into the pipes once you stop the blower. Use your filter's "waste" setting or a submersible pump to drop the water level to approximately 4–6 inches below the lowest plumbing orifice, usually the return jet. You will know it worked when the water line is clearly below the circular return fittings and the rectangular skimmer opening.

Step 2: Drain the Pump and Filtration System

You must remove all water from the mechanical equipment to prevent the casing from cracking during a freeze. Open the drain plugs on your pump housing, filter tank, and heater (if applicable), allowing the water to spill out onto the equipment pad. Move the multi-port valve handle to the "Winterize" or "Closed" position to allow air to flow freely through the internal gaskets. You will know it worked when water stops dripping from the drain ports and the pump basket area is empty.

Step 3: Connect the Blower to the Plumbing

This step establishes the air pressure needed to displace the water sitting in your underground or flexible lines. Insert the shop vacuum hose into the pump’s intake (the pipe coming from the skimmer) or the pump basket outlet leading toward the filter. Use duct tape or a specialized threaded PVC adapter to ensure the connection is airtight so that no pressure is lost. You will know it worked when you turn on the vacuum and hear a distinct change in motor pitch as it begins to push against the water column.

Step 4: Blow Out the Return Lines

Clearing the return lines is vital because these are often the most exposed pipes in an above-ground setup. Direct the air from the blower through the filter (on "Recirculate" setting) or bypass the filter to force air toward the return jets in the pool wall. Watch the return fitting; you should see a massive spray of water followed by a steady stream of air bubbles. You will know it worked when only air is misting out of the return jet; at this moment, quickly insert a rubber expansion plug and tighten it to seal the line while the air is still blowing.

Step 5: Clear the Skimmer Line and Add Antifreeze

The skimmer line is susceptible to "heaving" if water freezes and expands inside the vertical pipe. Switch your blower connection to push air from the pump back toward the skimmer. Once the water is evacuated and air is blowing steadily into the skimmer bucket, pour one gallon of non-toxic pool antifreeze into the line. You will know it worked when you see the colored antifreeze begin to bubble or sit in the bottom of the skimmer, at which point you should install a "Gizzmo" or expansion plug to seal the pipe.

Step 6: Verify the Seal and Secure the Equipment

The final step ensures that no moisture can re-enter the system through condensation or precipitation. Double-check that all plugs are tightened and that the pump and filter drain plugs are stored safely in the pump basket for the winter. C&D’s Installers recommends a final "tug test" on all expansion plugs to ensure they won't slip out under the pressure of winter ice. You will know it worked when the lines remain filled with air/antifreeze and the equipment remains dry through the first frost.

What to Do If Something Goes Wrong

The shop vac doesn't have enough power to bubble the returns. This usually happens if the water level hasn't been lowered enough or if there is a leak in your hose connection. Ensure the water is 6 inches below the jets and use more duct tape to seal the vacuum hose to the pipe.

Water keeps trickling back into the skimmer after plugging. This indicates a faulty expansion plug or a crack in the skimmer housing. Replace the rubber plug with a new one and check the housing for hairline fractures that may need a winter-grade sealant.

The blower motor is overheating. Shop vacuums are not designed to run against high backpressure for long periods. If the air isn't moving, turn the vacuum off immediately, check for a closed valve in the system, and allow the motor to cool for 15 minutes before trying again.

What Are the Next Steps After Blowing Out Lines?

Once your lines are safely cleared and plugged, your next priority is chemical balancing for the dormant season. Adding a winterizing chemical kit will prevent algae growth during the early spring thaw. After chemicals are added, you should proceed to install your winter cover. For homeowners in the Mid-Atlantic, choosing between a solid or mesh cover is a critical decision; you can explore the pros and cons of each in our Solid vs. Mesh Winter Covers guide. Finally, ensure your cover pump is functional to prevent heavy water accumulation from damaging your pool walls.

Frequently Asked Questions

Can I use a leaf blower instead of a shop vac?

While some high-powered leaf blowers can work, they are often difficult to seal against pool plumbing. A shop vac is preferred because the circular hose is easier to adapt to 1.5-inch PVC pipes using standard fittings or tape.

Is pool antifreeze the same as automotive antifreeze?

No, you must never use automotive antifreeze (ethylene glycol) in a pool as it is highly toxic to humans and can damage pool liners. Always use non-toxic propylene glycol, which is specifically formulated for swimming pool plumbing.

How do I know if the lines are completely empty?

You can confirm the lines are clear when the "burping" sound of water at the return jet turns into a constant, high-velocity "hiss" of air. C&D’s Installers recommends blowing air for an additional 30 seconds after the water stops to ensure no pockets remain in low spots.

Do I need to blow out the main drain on an above-ground pool?

Most above-ground pools do not have a main drain, but if yours does, you must blow air until bubbles rise from the floor of the pool. You then quickly close the valve at the equipment pad to create an "air lock," as you cannot easily plug a main drain underwater.

Should I leave the drain plugs out of my pump all winter?

Yes, it is best practice to leave the drain plugs out and store them in the pump basket. This allows any incidental moisture from snowmelt or condensation to drain out rather than pooling and freezing inside the plastic housings.

Sources:
[1] Mid-Atlantic Pool Association, "Winter Damage Statistics and Prevention," 2025.
[2] C&D’s Installers Internal Technical Bulletin, "CFM Requirements for DIY Winterization," 2026.

Related Reading:

• The Complete Guide to Above Ground Pool Installation and Long-Term Ownership in 2026: Everything You Need to Know
• Is Professional Pool Winterization Worth It? 2026 Cost, Benefits, and Verdict
• How to Clean and Store a DE Filter for Winter: 6-Step Guide 2026
• What Is a Pool Cover Pump? The Essential Tool for Solid Winter Covers

Related Reading

For a comprehensive overview of this topic, see our The Complete Guide to Above Ground Pool Installation and Long-Term Ownership in 2026: Everything You Need to Know.

You may also find these related articles helpful:

• 20 Gauge vs. 25 Gauge: Which Pool Liner Is Better for Pennsylvania Winters? 2026
• How to Prepare Your Backyard for a Professional Above-Ground Pool Installation: 6-Step Guide 2026
• How to Coordinate Water Delivery with a Professional Above Ground Pool Installation: 5-Step Guide 2026

Frequently Asked Questions

Can I use a leaf blower instead of a shop vac to blow out pool lines?

While some leaf blowers have enough power, they are difficult to connect to plumbing. A 5.0+ Peak HP shop vacuum with a blower port is the recommended DIY tool because its hose can be easily sealed to 1.5-inch pool pipes.

Is it safe to use automotive antifreeze in pool pipes?

No, automotive antifreeze is toxic and will damage your pool. You must use non-toxic propylene glycol antifreeze, which is safe for swimming pool systems and liners.

How do I know when all the water is out of the lines?

The lines are clear when the sputtering and splashing at the return jet stops and is replaced by a steady, loud hiss of air. It is best to continue blowing for 30-60 seconds after the water stops to ensure low spots are vacated.

What if my above-ground pool has a main drain?

If you have a main drain, blow air until bubbles rise from the pool floor, then quickly close the intake valve at the pump to create an ‘air lock.’ This prevents water from rising back up into the pipe.