The Dolphin S400 brings in-store exclusive functionality to inground pools up to 50 feet, featuring waterline cleaning, an anti-tangle swivel, and the MyDolphin Plus mobile app for remote control. Its lightweight design and multi-layer filter provide easy maintenance, but it may fall short for users looking for more filter customization options. Though it’s designed for thorough coverage, some may find more affordable alternatives that deliver similar performance, especially given the S400's premium price.
Cleans the floor, walls and waterline
Built for in ground pools up to 50 ft
Top Access filtration
Programmable weekly cleaning schedule
Specs
Pool size
Up to 50 ft
Coverage
Floor, Walls and Waterline
Cleaning cycle
1.5, 2 hours
Cable
60 ft
Robot weight
18.5 lb
Warranty
2 years
Brand
Dolphin
Delivery
Free 1–3 day FedEx shipping Estimated delivery from 1 business day to 3 business days near .
Fully tracked delivery to the 48 contiguous states
Authorized Dolphin Dealer
Full manufacturer warranty and U.S.-based support
The S400 in detail
Built by Maytronics, the Dolphin S400 is a corded robot for in-ground and above-ground pools up to 50 feet long. It cleans floors, walls and the waterline, with active scrubbing and two standard brushes. Its cable swivel helps reduce tangles as it moves, while a top-access multi-layer filter collects debris.
It suits owners who want MyDolphin™ Plus app control, a weekly timer and delayed starts. The default cycle is 2 hours, with 1.5- and 2.5-hour options also available. A caddy is included. Maytronics lists it as a pool-store exclusive with a $1,799 list price. Poolbots does not sell the Dolphin S400. This page provides model information and support.
Who the S400 is for
The Dolphin S400 suits in-ground and above-ground pools up to 50 feet long, including rectangular, round, free-shape and kidney-shaped pools. It is a good match for owners who want floor, wall and waterline cleaning, scheduled cycles and a filter they can lift out from the top.
Simple plug-in setup
Connect the power supply, place the robot in the pool and start a cleaning cycle.
App control and scheduled cleaning
Control the robot through MyDolphin™ Plus. A weekly timer and delayed start let you plan cleaning.
Active scrubbing
The Dolphin S400 combines two standard brushes with active scrubbing and floor, wall and waterline coverage.
Top-access multi-layer filter
Lift the filter out from above, open its bottom and rinse it clean. A full-filter indicator signals when it needs attention.
Three cleaning times
Choose a 1.5-, 2- or 2.5-hour cleaning cycle. The default cycle runs for 2 hours.
The S400 up close
The S400 at a glance
What we like
Energy Efficient Motors
Waterline Cleaning
Schedule Cleanings - Run every 24, 48, or 72 hours
Anti-Tangle Swivel - Prevents Tangles
2 High Speed Scrubbing Brushes
What to know
Not a great value when compared to alternative robots
No Smartphone App
Better Value Units Available
Shorter Warranty Than Premium Robots
Lacks multiple filter options - Similar units come with 2+
S400 Product Video
Try It for 30 Days
Try any robot in your pool for 30 days. We believe a pool robot is an investment, and we know you'll love it. Which is why we have a 30 Day Trial. If you don't love it, simply return the robot. Unlike the other guys, we never charge a restocking fee or any other fees - meaning no restocking fee ever.
Here at Poolbots, we carry only the top models for the top brands. All of our pool robots are backed by a full manufacturer's warranty - not prorated or limited to cycles like other pool robots.
Weather-resistant cover protects your Dolphin S400 and caddy from sun, rain, and debris.
$99
Compare Dolphin S400
See how the Dolphin S400 stacks up against the closest models by price — compare pool fit, key features, and the standout benefits of each. Want a full breakdown? Use the head-to-head links below, or chat with our pool experts.
John Rodriguez of "Poolbots" recommended the Dolphin Sigma for my 20x40 Saltwater pool. I have to say, "John was correct...this thing is a beast!" I live in the SoCal desert and the Sigma picks up the fine dirt, sand and phosphate residue. John answered all of my questions. Shipping was quick! Semper Fi — USMC 1984-1992
S
Stephano Rivera
"Patient, knowledgeable, and took the time to answer all of my questions thoroughly."
Jose provided clear and detailed information about the pool cleaners. His professionalism made the whole process stress-free.
J
Jon Olson
Local Guide · 15 reviews
I wish I would have converted my pressure side vac to an electric pool robot a long time ago. It cleans 10x better and completes my pool in 90 minutes.
T
Teresa Honeycutt
"Without her multiple emails to the company, this would never have happened."
Shannon assisted me with an ongoing issue since May 2025 with a manufacturer. She went the extra mile and followed up!
K
kdware12
3 reviews · 1 photo
Excellent customer service and super fast shipping. I highly recommend Poolbots for all your needs.
L
Larry Conti
Local Guide
"I asked to speak to a human — and was told 'I am a human!'"
I clicked "chat" expecting AI. I was so pleased this company still has human interaction. John was great.
P
pleasetakethis
6 reviews · 3 photos
I really appreciate the opportunity to try a robot and be able to swap it. Great return process and customer service.
S
Steve Waters
"A far better and more informed purchase option than Amazon."
John went out of his way to go over all the different units and what might be best for my pool. Absolutely awesome customer service.
T
Timothy Foley
"Truly treats you like family."
I had a few issues with my product, but Jose did an amazing job helping me and stayed in constant communication throughout the entire process.
J
Jaime Nahman
"Jose helped fix my incorrect shipping address... saved me a lot of grief."
His help was excellent. Quick intervention prevented a lost shipment.
S
Shane Cheatham
"Because of John, I bookmarked Poolbots and will use them for everything."
He was very knowledgeable, professional, and interested in getting you the right product — not just making a sale.
K
Kevin Miller
"John was amazing. I had no idea what I needed."
He was very patient. After giving me multiple options and explaining the differences, he offered the perfect unit for my pool.
E
Edwina Erlemann
"Call John, you won't be sorry!"
John guided me through the process of selecting the best pool cleaner robot for my needs. Very highly recommend!
A
Andrea Price
"John was correct...this thing is a beast!" Picks up the fine dirt, sand and phosphate residue in the SoCal desert. Semper Fi — USMC 1984-1992
S
Stephano Rivera
"Patient, knowledgeable, and took the time to answer all of my questions thoroughly."
Jose provided clear and detailed information about the pool cleaners. His professionalism made the whole process stress-free.
T
Teresa Honeycutt
"Without her multiple emails to the company, this would never have happened."
Shannon went the extra mile and followed up!
J
Jon Olson
I wish I would have converted my pressure side vac to an electric pool robot a long time ago. It cleans 10x better and completes my pool in 90 minutes.
L
Larry Conti
"I asked to speak to a human — and was told 'I am a human!'"
I was so pleased this company still has human interaction. John was great.
S
Steve Waters
"A far better and more informed purchase option than Amazon."
Absolutely awesome customer service from John.
K
kdware12
Excellent customer service and super fast shipping. I highly recommend Poolbots for all your needs.
T
Timothy Foley
"Truly treats you like family."
Jose stayed in constant communication throughout the entire process.
J
Jaime Nahman
"Jose helped fix my incorrect shipping address... saved me a lot of grief."
His help was excellent. Quick intervention prevented a lost shipment.
P
pleasetakethis
I really appreciate the opportunity to try a robot and be able to swap it. Great return process and customer service.
S
Shane Cheatham
"Because of John, I bookmarked Poolbots and will use them for everything."
He was very knowledgeable, professional, and interested in getting you the right product — not just making a sale.
K
Kevin Miller
"John was amazing. I had no idea what I needed."
Very patient, offered the perfect unit for my pool.
E
Edwina Erlemann
"Call John, you won't be sorry!"
Guided me through selecting the best robot for my needs.
Customer Reviews
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Questions & Answers
Does Poolbots charge any restocking fees in your 30 Day Trial?
No, we never charge a restocking fee ever! We know a robotic pool cleaner is a big investment, which is why we offer 30 Day Trials on all robotic pool cleaners!
How long is the Dolphin S400's warranty?
As a proud Authorized Dealer for Dolphin, the Dolphin S400 includes a full 2 year warranty from date of purchase.
Does Dolphin S400 need a booster pump to work?
No! The Dolphin S400 is plug and play! All you need to do is unbox the unit and plug it into an outlet. No setup or assembly required!
My Dolphin S400 gets stuck on drains, how can I fix this?
With a main drain clip on, you can successfully avoid the robot getting stuck on your drain.
Does the Dolphin S400 work with saltwater pools?
Yes. The Dolphin S400 works with all types of pools, including freshwater and saltwater.
What types of pools does the Dolphin S400 work with?
If you have any questions or wonder if this is the right robot for you, contact us or view our Pool Robot Guide.
Does the Dolphin S400 have WiFi/Bluetooth?
Yes, the Dolphin S400 has wifi and bluetooth that allows you to connect and control the robot from the app.
Does the Dolphin S400 have an app?
Yes, the Dolphin S400 has an app to control the robot.
How long does Dolphin S400 run for?
The Dolphin S400 cleans for 1.5, 2 hours. You can set the robot to run daily via its included programmable timer.
How much does Dolphin S400 weigh?
The Dolphin S400 weighs 18.5 lb.
How does Dolphin S400 work?
The Dolphin S400 works as an automatic robotic pool cleaner. It will vacuum, scrub, and automate your pool cleaning. With a plug and play design, all you need is an outlet to plug it into and you're good to go. No booster pump or assembly needed.
Does Dolphin S400 pick up leaves?
The Dolphin S400 can pick up leaves. While not as effective as the Dolphin Premier, which includes an oversized leaf bag.
Does Dolphin S400 pick up sand, algae, or small debris?
The Dolphin S400 cannot perform as well as robots with NanoFiltration. As the mesh filters on Dolphin S400 cannot capture small particles like the newer Gen-2 NanoFilters. See all robots with NanoFiltration here.
Yes, the Dolphin S400 cleans your entire pool - including the floor, walls, and waterline.
Can the Dolphin S400 be plugged into an extension cord?
Yes it can!
I can power my Dolphin S400 on but it does not move
If your Dolphin powers on but does not move, try checking the tracks for any debris or obstructions. Also, check the drive motor and impeller for any damage or wear. If you are still having issues, contact Maytronics customer support for further assistance.
My Dolphin S400's power supply does not turn on when I press the power button
If your Dolphin's power supply is not turning on, check to make sure it is properly plugged in and that the outlet it is plugged into is working. If the power supply is still not turning on, contact Maytronics customer support for further assistance.
My Dolphin S400 is not cleaning the pool properly
If your Dolphin S400 is not cleaning the pool properly, try checking the filter bag for any debris or blockages. Also, check the brushes and tracks for any damage or wear. If you are still having issues, contact Maytronics customer support for further assistance.
What are the handles and the floats on my Dolphin for?
The handles on your Dolphin are for lifting and carrying the unit, while the floats are designed to help your Dolphin navigate around the pool and maintain proper buoyancy.
There seems to be something stuck in my Dolphin S400's tracks – how can I get it out?
To remove any debris or obstructions from your Dolphin's tracks, turn off the power supply and carefully remove the tracks from the unit. Use a soft brush or cloth to clean the tracks and remove any debris. Once clean, reattach the tracks to the unit.
The cord is connected to the robot's power unit, but the power unit LED indication is off
If the power unit LED indication is off even when the charger is connected, please try the following steps: 1) Unplug the power supply from the outlet and wait for 10 seconds. 2) Plug the power supply back in and check if the LED indication turns on. 3) If the LED indication still does not turn on, contact Maytronics customer support for further assistance.
Why should I register my robot?
Registering your Dolphin robotic pool cleaner allows you to receive important product updates and notifications, as well as access to exclusive content and promotions.
