8 Essential Winterizing Plugs and Blow-Out Tools for a Backyard Pool

As autumn leaves begin to blanket the backyard, pool owners face the inevitable task of closing down their personal swimming oases for the cold months ahead. Leaving even a small amount of water trapped inside underground plumbing lines can lead to catastrophic pipe bursts once freezing temperatures arrive. Equipping yourself with the right selection of winterizing plugs and blow-out tools is the single best way to protect your investment and ensure a stress-free reopening next spring.

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Why Proper Pool Winterization Prevents Costly Damage

Water expands by approximately nine percent when it freezes, exerting immense pressure on whatever container holds it. In a backyard pool, this expansion occurs inside rigid PVC pipes, delicate pump housings, and expensive filtration units. Without a proper winterization routine, a single hard freeze can crack underground plumbing lines, leading to thousands of dollars in excavation and repair costs.

Beyond the hidden plumbing, freezing water can easily wreck visible pool equipment like skimmers and chlorinators. Cracks in these components are not just inconvenient; they often require complete equipment replacements that disrupt your spring launch. Taking the time to properly seal and clear the system now acts as an inexpensive insurance policy for your summer recreation.

How to Clear Pool Lines Before Freezing Temperatures

Clearing your pool lines is all about displacing water with air and keeping it out until spring. This process, known as “blowing out” the lines, uses high-volume air to push water out of the pipes through the return jets and skimmers. Once the water is evacuated, heavy-duty winter plugs are quickly inserted to create an airtight seal that prevents water from seeping back in.

Timing is everything when preparing for the off-season. You want to initiate this process after the pool water has been thoroughly cleaned and balanced, but well before the first overnight frost is forecasted. Rushing through a blowout with substandard tools often results in trapped pockets of water that eventually freeze and fracture your plumbing.

Pool Line Blower – Cyclone 3 HP Bypass Line Blower

A dedicated line blower is the heart of any successful pool winterization kit, providing the high-volume, low-pressure air needed to push gallons of water out of deep underground plumbing. Standard shop vacuums or small air compressors simply lack the volume (CFM) required to clear long pipe runs, often leaving dangerous pockets of water behind. This tool ensures that your main drains, returns, and skimmer lines are completely bone-dry before the freeze sets in.

The Cyclone 3 HP Bypass Line Blower is the industry standard for this task because of its powerful commercial-grade motor and durable plastic housing. It delivers up to 130 CFM of air flow, which is more than enough muscle to clear out lines in deep in-ground pools. The built-in bypass valve protects the motor from overheating when pressure backs up, ensuring this unit lasts for years of seasonal closures.

• Motor Power: 3 Horsepower, 120 Volt
• Airflow Capacity: 130 CFM / 160 inches of sealed water lift
• Hose Connection: 2-inch quick-disconnect fitting
• Best For: Heavy-duty in-ground pool blowouts and multi-port systems

While this blower is highly effective, users must handle it with care to avoid over-pressurizing delicate pool fittings or older thin-walled PVC pipes. It is an exceptional investment for dedicated pool owners who want to bypass professional pool service fees year after year. However, it may be overkill for owners of small, shallow above-ground pools who can get by with smaller utility blowers.

Threaded Return Plug – Hayward SP1022C 1.5-Inch Plug

Once the water is cleared from your pool’s return lines, you need a reliable way to seal the wall fittings to prevent pool water from draining back into the pipes. Threaded plugs screw directly into the female threads of your wall return fittings, creating a solid mechanical barrier. Without these, heavy winter rains or snowmelt will refill the lines, rendering your blowout efforts useless.

The Hayward SP1022C 1.5-Inch Plug is the premier choice for standard return lines due to its rugged, UV-resistant plastic construction and precision threading. It features a heavy-duty o-ring that compresses tightly against the fitting wall to block out moisture. The slotted face allows for easy installation and removal using a standard coin, flathead screwdriver, or a specialized plug wrench.

• Thread Size: 1.5-inch MIP (Male Iron Pipe)
• Material: High-grade white ABS plastic
• Gasket Type: Included rubber O-ring
• Best For: Standard threaded pool return jets and cleaner lines

Before buying, verify that your return fittings actually have internal threads, as some older or non-standard pools utilize smooth wall fittings. Ensure the O-ring is seated flat during installation to avoid pinching, which can cause slow, microscopic leaks over the winter. This plug is ideal for standard in-ground and above-ground pools with threaded return lines, but useless for smooth-bore pipe openings.

Rubber Expansion Plug – Anderson Winterizing Plug No. 10

Not all pool openings are threaded, which is where rubber expansion plugs become indispensable. These plugs sit inside smooth pipe openings, and as you tighten the wing nut, the rubber body compresses and expands outward against the pipe walls. This creates a highly reliable friction fit that blocks water and air, even under significant thermal expansion.

The Anderson Winterizing Plug No. 10 stands out because of its premium-grade neoprene rubber and corrosion-resistant nylon wing nut assembly. Unlike cheap generic plugs that crack in sub-zero temperatures, this Anderson plug remains pliable and maintains its airtight seal throughout the harshest winters. The heavy-duty stainless steel bolt ensures the compression mechanism will not rust or seize over months of exposure to pool chemicals.

• Size Range: Fits 1.5-inch to 1.75-inch pipe openings (Size 10)
• Hardware Material: Stainless steel bolt with nylon wing nut
• Body Material: Weather-resistant neoprene rubber
• Best For: Smooth return inlets, cleaner lines, and skimmer bottoms

Users should avoid over-tightening the wing nut, as excessive force can strip the threads or distort the rubber, causing it to slip out of the pipe. It is perfect for pool owners dealing with unthreaded return lines or damaged pipe openings where threaded plugs will not grip. It is not suitable for pipes smaller than 1.5 inches or larger than 1.75 inches.

Skimmer Freeze Plug – Gizzmo Ultra 16-Inch Skimmer Bottle

Skimmers are highly vulnerable to freeze damage because they sit right at the pool’s water line where ice forms first and thickens most. A skimmer freeze plug acts as a sacrificial barrier; when ice expands inside the skimmer throat, it crushes the hollow plastic plug rather than cracking the expensive skimmer walls. Simultaneously, it seals the plumbing line at the bottom of the skimmer bucket to prevent water from re-entering the underground pipes.

The Gizzmo Ultra 16-Inch Skimmer Bottle is the gold standard for protecting deep-well skimmers. It features a heavy-walled, blow-molded plastic body designed to absorb expansion pressure, alongside a 1.5-inch threaded male bottom that screws directly into the skimmer drain. This dual-action design keeps water out of the pipes while neutralizing ice pressure inside the skimmer well itself.

• Length: 16 inches (designed for deep skimmers)
• Thread Type: 1.5-inch and 2-inch dual threads
• Material: High-density, crushable polyethylene
• Best For: In-ground pool skimmers with deep wells

Always wrap the threads of the Gizzmo with Teflon tape before screwing it in to ensure a watertight seal and easy removal in the spring. This model is ideal for deep in-ground pool skimmers, but it will be too tall for shallow above-ground pool skimmers, which require the shorter 9-inch standard Gizzmo version.

Blow-Out Expansion Plug – Anderson Plug with Valve

Traditional pool blowouts often require two people: one to run the blower and another to quickly plug the line as the air escapes. A blow-out expansion plug solves this logistical challenge by allowing you to blow air directly through the plug itself. This tool stays securely inside the pipe while you pump air through its built-in valve, keeping the system pressurized and water-free.

The Anderson Plug with Valve features a heavy-duty rubber expansion body integrated with a standard tire-style Schrader valve. This allows pool owners to connect an air hose directly to the plug, blow out the line until it bubbles at the pool wall, and let the valve automatically seal when the air hose is removed. It streamlines the winterization process, making it a safe, efficient one-person job.

• Valve Type: Standard Schrader valve (brass)
• Body Size: 1.5-inch expansion diameter
• Material: Galvanized steel hardware with durable rubber expansion ring
• Best For: Solo pool winterization and hard-to-reach plumbing runs

Because air is introduced through a relatively small valve, it takes longer to push high volumes of water out compared to a wide-mouth blower hose. It is an exceptional choice for solo pool DIYers looking for a controlled, systematic blowout process. It is not recommended for those who prefer high-volume, rapid-purge methods using dedicated commercial blowers.

Blow-Out Adapter – Camco 36153 Brass Blow Out Plug

Before you can push air through your pool’s equipment pad plumbing, you need a secure way to connect your air compressor to the system. A blow-out adapter bridges the gap between your standard compressor hose and the threaded drain ports on your pump, filter, or heater. Without a secure adapter, holding an air nozzle against a drain port is inefficient, messy, and potentially dangerous due to escaping high-pressure air.

The Camco 36153 Brass Blow Out Plug is a rugged, simple tool that screws directly into standard threaded pool equipment ports. Made from solid brass, it resists cross-threading and stands up to the high air pressures required to clear stubborn water pockets. The quick-connect plug on the opposite end snaps easily into standard air compressor couplers, creating a hands-free, airtight connection.

• Material: Solid brass construction
• Thread Size: 1/2-inch male NPT to quick-connect plug
• Durability: Rust-proof and burst-resistant
• Best For: Connecting standard air compressors to heater and pump drain ports

Note that this adapter features a 1/2-inch thread, so you may need a reducer or adapter bushing if your pool pump or chlorinator utilizes 1/4-inch or 3/4-inch drain plugs. It is perfect for pool owners who already own a standard home air compressor and want a simple hookup for winterization. It is not designed for high-volume blowers that use wide 1.5-inch or 2-inch hoses.

Double Expansion Plug – Anderson Extended Double Plug

Sometimes, standard single-rubber expansion plugs are not enough to seal a line, especially if the pipe opening is warped, chipped, or sits deep inside a pool wall fitting. A double expansion plug uses two separate rubber rings stacked on a single bolt shaft. This dual-seal configuration provides twice the gripping surface and acts as a redundant barrier against water intrusion.

The Anderson Extended Double Plug is engineered specifically for troublesome, deep-set, or out-of-round pipe openings. Its extended shaft allows you to seat the lower rubber ring past damaged surface plastic while the upper ring seals the outer edge of the pipe. The extra-long nylon wing nut assembly makes it easy to tighten deep within the wall fitting without scraping your knuckles.

• Plug Configuration: Dual rubber expansion rings
• Shaft Length: Extended length for deep-set seals
• Sizes Available: Standard 1.5-inch and 2-inch options
• Best For: Damaged, deformed, or deep-set plumbing lines

Due to its dual-ring design, this plug requires more physical effort to compress and seat properly inside the pipe. It is the ultimate problem-solver for older pools with deteriorating PVC fittings or rough-cut pipe edges. However, for pristine, newly installed pools with flush fittings, a standard single-expansion plug is usually much easier to install.

Pump Drain Plug – Hayward SPX1700FG Plug with Gasket

Leaving water inside your pool pump’s strainer basket over the winter will almost certainly crack the plastic housing or damage the internal impeller when it freezes. Every pool pump features small drain ports at the bottom designed to evacuate this residual water. Replacing these small, easily lost plugs with high-quality spares ensures your pump remains sealed tight during the active season and drains completely in the winter.

The Hayward SPX1700FG Plug with Gasket is the OEM replacement standard for Hayward Super Pumps and MaxFlo pumps. It comes with a thick rubber gasket that prevents leaks under high operating pressures and is made of durable, UV-stabilized polymer. Keeping a few of these on hand ensures you are never sidelined by a lost or cross-threaded plug during your autumn shutdown.

• Thread Pattern: Standard Hayward 1/4-inch NPT
• Material: High-durability black polymer
• Seal Type: Heavy-duty rubber gasket included
• Best For: Hayward pump strainers, housings, and select chlorinators

While this is a highly standardized plug, it is critical to confirm your pump model’s thread size, as some competing brands use non-standard metric threads or larger 3/8-inch plugs. Hand-tighten these plugs only; using a wrench can easily strip the plastic threads on the pump housing, leading to a costly repair. This is an essential spare part for Hayward pump owners but will not fit Pentair or Jandy pumps requiring different thread specs.

Step-by-Step Guide to Blowing Out Pool Lines Safely

Before starting your blowout, lower the pool’s water level below the skimmer mouth and return jets to prevent water from splashing back into the lines. Hook up your line blower to the pump basket intake or the pool filter’s multi-port valve set to the “Recirculate” position. This allows the air to bypass the filter media and head directly into the plumbing lines.

Turn on the blower and clear the lines furthest from the pump first, working your way closer to the equipment pad. You will see a massive geyser of water blast out of the pool’s return jets. Let the air run until you see only a fine mist or dry air escaping, then immediately slide your winterizing plug into the fitting and tighten it securely while the air is still flowing.

Once the return lines are sealed, switch the airflow toward the skimmer lines. After the skimmers are completely cleared of water, install your Gizzmo or expansion plugs. Finally, blow out the main drain line at the bottom of the pool until you see a steady stream of air bubbles, then quickly close the valve at the equipment pad to lock in an air lock, which naturally keeps water from rising back up the pipe.

Storing Your Pool Winterization Gear for Next Season

When spring finally arrives and it is time to open the pool, how you handle and store your winterizing gear determines its lifespan. As you remove the plugs, rinse them thoroughly with fresh water to remove any concentrated pool chemicals, salt, or winterizing antifreeze. Allow all rubber plugs, Gizzmos, and adapters to air-dry completely in the sun before packing them away.

Store your winterization gear in a heavy-duty, sealable plastic bin kept in a climate-controlled area like a basement or garage cabinet. Extreme heat or cold in an outdoor shed can cause rubber expansion plugs to dry rot, crack, or lose their elasticity over the summer. Keeping all plugs, gaskets, and blowout adapters in one organized container ensures you won’t be hunting for misplaced parts when autumn rolls around again.

Taking the time to properly clear and plug your pool lines is the ultimate defense against winter’s destructive forces. With the right blow-out tools and premium expansion plugs in your arsenal, you can rest easy knowing your backyard investment is safe from freeze damage. When spring returns, your pool will be ready for a smooth, trouble-free opening and another season of summer fun.