Polaris P39 Vs 3900

Shopping for a powerful pressure-side pool cleaner and stuck between the Polaris P39 and the Polaris 3900 Sport? You’re not alone. These two cleaners look alike for a reason: the P39 is essentially a dealer-exclusive version of the 3900 Sport with a few package and warranty differences. In this beginner-friendly guide, I’ll explain how they compare, what really changes day to day in your pool, and how to choose the one that fits your budget, pool type, and maintenance style.

Quick Overview

What These Cleaners Are

Both the Polaris P39 and Polaris 3900 Sport are pressure-side, in-ground pool cleaners. They run off a dedicated booster pump line (not your skimmer) and use powerful venturi jets to pull in debris. They’re designed for medium to large pools, especially those with lots of leaves, acorns, or heavy debris that can overwhelm suction cleaners or robos with small canisters.

Who They’re Best For

Choose a pressure-side cleaner like the P39 or 3900 if you have trees shedding into the pool, a large surface area, or you prefer a cleaner that keeps debris out of your main filter system. They shine in pools where leaves and twigs are a daily reality. They’re also great if you want reliable coverage with simpler maintenance than many robotic cleaners.

Key Similarities

Pressure-Side Power (Booster Pump Required)

Both models need a dedicated booster pump line to work. The Polaris PB4-60 is the most common match. This setup keeps debris out of your skimmer and main filter because the cleaner has its own pressurized water supply. If your pool doesn’t have a booster line, factor in the cost to add one or consider a robotic alternative.

Drive and Traction

Both use an all-wheel drive system with a strong chain and PosiDrive gearing for good torque and climbing. The wide tires give them grip on plaster, pebble, and some smooth surfaces. With proper flow, they climb walls and handle coves well.

Debris Handling and Bag Capacity

They’re built for big debris. The large, zippered bag sits on top and is easy to remove and empty. It can hold a lot—much more than most robot canisters—so you don’t have to stop mid-clean to shake it out. This makes them ideal for leaf-heavy seasons.

Coverage and Back-Up Valve

Each cleaner has an in-line back-up valve on the feed hose. Every few minutes it pulses to pull the unit away from tight spots (ladders, main drains). This is a key reason pressure cleaners can be left to roam for hours without babysitting.

Important Differences

Warranty and Where You Buy

Polaris positions the P39 as a trade/dealer-exclusive model. When purchased through authorized dealers, it often carries an extended warranty compared to widely available online 3900 Sport units. Exact terms can vary by retailer and region, so check the warranty card before buying. If a longer warranty matters to you, the P39 usually wins.

Included Accessories

The P39 commonly ships with the TailSweep PRO (a safety/comfort add-on that tames the sweep hose spray) in the box. Many 3900 Sport packages also include TailSweep PRO today, but some older or discounted bundles may not. Some P39 bundles may also include an extra fine-mesh or silt-oriented bag; this depends on the dealer. Ask what’s in the box—extras can save you money and hassle.

Price and Value

The P39 typically costs a bit more up front but can include extras and an extended warranty that add long-term value. The 3900 Sport is easier to find online and may have sharper sale pricing. If you don’t need extra accessories or the extended warranty, the 3900 can be the more budget-friendly route.

Aesthetics and Minor Tweaks

Cosmetics and trim may differ slightly (badging, colors, bundled hose type), but cleaning performance is fundamentally similar. Base your decision on warranty, included accessories, dealer support, and price more than looks.

Performance in Real Pools

Leaves, Acorns, and Heavy Debris

Both the P39 and 3900 handle heavy leaf loads better than most suction cleaners and many robots. Their venturi jets lift debris into the top bag quickly, and the wide intake reduces clogging. If you open your pool to a backyard jungle every fall, either model is a strong choice.

Sand, Silt, and Fine Dust

With the standard all-purpose bag, they’ll pick up a fair amount of fine debris but not as thoroughly as a robot with a fine filter cartridge. For dusty pools, get a fine-mesh or silt bag. Many P39 bundles include one, while 3900 buyers may need to purchase it separately. With the fine bag installed and flow tuned, both units do a respectable job on silty steps and floors.

Walls, Steps, and Waterline

Both models climb walls when the flow is set correctly and the tires are in good shape. They may not scrub a waterline the way some robots do with brushes, but their sweep hose helps loosen dirt on verticals. For step treads and benches, coverage is hit-or-miss due to size and buoyancy. If steps are your biggest pain point, supplement with a quick manual brush or consider a robot that targets steps.

Large or Irregular-Shaped Pools

The back-up valve and all-wheel drive help them navigate complex shapes. For extra-long pools, you may need additional hose sections to reach the far end. Expect them to methodically roam and eventually cover everything during a typical 2–3 hour run, and then some owners like to run them daily in peak debris season.

Installation and Setup Tips

What You Need

– A dedicated booster pump line and a compatible booster pump (commonly Polaris PB4-60).
– A wall fitting for the return line where the cleaner connects.
– The cleaner body, feed hose sections, floats, swivels, back-up valve, pressure relief valve, and debris bag (included with both models).
– A timer for the booster pump is helpful for consistent run cycles.

Step-by-Step Setup

1) Assemble the feed hose on the deck. Lay out sections, ensure swivels are on the correct ends, and add the back-up valve in-line where shown in the manual.
2) Size the hose to your pool. The total hose length should be the distance from the wall port to the deepest point of the pool plus one to two sections. Trim or add sections as needed.
3) Attach the universal wall fitting to your dedicated return port. Make sure the o-rings are lubricated and seated.
4) Connect the hose to the wall fitting and then to the cleaner. Confirm floats are near the back-up valve and along the hose as directed to prevent sinking and tangles.
5) Start the main circulation pump, then start the booster pump. The cleaner wheels should turn at a steady pace and the sweep hose should gently move.

Fine-Tuning Flow

– Wheel speed: Count wheel revolutions. Aim for the rate specified in your manual (often around 28–32 RPM). Adjust the pressure relief valve at the wall fitting until you hit the sweet spot.
– Hose balance: With the cleaner in the pool, it should sit slightly nose-down. If it pops wheelies or flips, reduce flow or adjust floats.
– Back-up timing: Watch the back-up valve. It should engage periodically to pull the cleaner out of corners, then return to normal operation.
– TailSweep control: Install the TailSweep PRO to stop the sweep hose from spraying out of the pool and wetting the deck or windows.

Maintenance and Ownership

Routine Care

– Empty the bag before it’s overstuffed; a heavy bag reduces climbing and mobility.
– Rinse the bag after dusty days to keep the mesh flowing freely.
– Check tires, bearings, and tail scrubber monthly during the season.
– Inspect hose swivels and floats; replace cracked or waterlogged parts.

Parts and Wear Items

Common wear parts include tires, tail scrubber, bag, hose floats, swivels, and sometimes the back-up valve. These are widely available and easy to swap. Keep a spare bag and tail scrubber on hand if your pool gets year-round use.

Troubleshooting Basics

– Cleaner stuck or not moving: Check for rocks in the wheels, verify wheel RPM, and confirm the booster pump is running. Inspect the back-up valve for constant leakage (it should only pulse periodically).
– Hose tangling: Ensure swivels rotate freely, reduce excess hose length, and make sure floats are placed correctly.
– Won’t climb: Increase flow slightly, clean or replace tires, and lighten the bag. Verify the cleaner’s nose points slightly downward in the water.
– Spraying water out of pool: Install or adjust TailSweep PRO and reduce pressure a notch.

Cost of Ownership

Energy Use

Booster pumps add operating cost. Many owners run the cleaner 1.5–3 hours per day during heavy debris seasons and less often when the pool is clean. If energy use is a major concern, a high-efficiency robotic cleaner uses less electricity but may require more frequent canister emptying during leaf season.

Bags and Parts Costs

Replacement bags and wear items are reasonably priced and easy to find. If your P39 bundle includes a fine-mesh bag and TailSweep PRO, you’ll save on early accessories. For the 3900, consider budgeting for TailSweep PRO and a fine bag if you need them.

Which One Should You Choose?

Choose the Polaris P39 if…

– You want dealer support and typically a longer or enhanced warranty.
– You like having TailSweep PRO and possibly a fine-mesh bag included right away.
– You prefer buying local and having a pro help with setup and tuning.

Choose the Polaris 3900 Sport if…

– You want a similar cleaning experience at a lower upfront price.
– You’re comfortable buying online and handling basic setup yourself.
– You don’t mind adding TailSweep PRO or a fine bag separately if your bundle doesn’t include them.

FAQs

Do both require a booster pump?

Yes. Both the P39 and 3900 Sport are pressure-side cleaners designed to run from a dedicated booster pump line. Without a booster pump, they won’t function properly.

Will they work in vinyl or fiberglass pools?

Yes, but ensure the tires are in good condition and the flow is set correctly to avoid excessive scuffing. Always follow Polaris’ surface recommendations for your specific model and bag type.

How long should I run the cleaner?

In heavy debris seasons, 2–3 hours per day is common. In lighter seasons, every other day or shorter cycles may be enough. Adjust based on what you see in your pool.

Do they pick up large leaves and small twigs?

Yes. These cleaners excel with leaves, small twigs, seed pods, and acorns. That’s their core strength over many robots and suction cleaners.

What about very fine dust?

Use a fine-mesh or silt bag for best results. The standard bag can miss ultra-fine dust that a robot with microfiltration might capture more easily.

How do I stop the tail from splashing windows and decking?

Install the TailSweep PRO and reduce the flow slightly. Position the return flow so the cleaner isn’t forced to spend time at the surface near the coping.

Conclusion

If you’re torn between the Polaris P39 and the Polaris 3900 Sport, remember this: performance is very similar because the platforms are nearly the same. The real differences are in warranty, included accessories, dealer support, and price. The P39, often a dealer-exclusive package, typically offers stronger warranty coverage and useful add-ons like the TailSweep PRO (and sometimes a fine bag). The 3900 Sport is easier to find online and can save money if you don’t need extras included—or if you don’t mind adding them later.

In leaf-heavy pools or large in-ground pools, both machines are workhorses. Set them up correctly, fine-tune the flow, keep the bag clean, and they’ll quietly keep your pool swimmable with minimal fuss. Pick the bundle and buying experience that fits you, and you’ll get the same dependable cleaning either way.