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Nautilus · Troubleshooting guide
Start with the power supply and cable connections when troubleshooting Dolphin Nautilus CC Plus, then check the filter, impeller, tracks or brush as needed. This model's guide includes 25 fixes, and Poolbots' pool experts can help by live chat or phone. Every fix below is rewritten in plain English and sorted by what the robot is doing wrong, with the genuine part that fixes it.
Nautilus CC Plus model page Manual & videos Warranty & claims
Quick checks
Start here
Maytronics' own diagnostic flow begins with the power supply, and so does this page. Unplug the supply before you touch the robot. Where a check ends in a worn part, the genuine replacement is linked under it.
With the robot out of the pool, unplug the blue cable from the power supply and switch the supply on by itself. If it will not power up, or shuts off on its own, the power supply needs service, not the robot.
Worn? Replace it:Dolphin Power Supply 180W Weekly Timer $399 All Nautilus CC Plus parts →
Line up the notch on the plug, push it fully home and tighten the locking ring. A loose plug is the most common cause of a robot that will not start.
Worn? Replace it:Maytronics USA Switching 3W Cord $16.1456-Foot Two-Wire Communication Cable With Swivel $229.99 All Nautilus CC Plus parts →
Unplug the supply, turn the robot over and spin each brush by hand. Open the impeller cover with a Phillips screwdriver and pull out any hair or debris.
Worn? Replace it:Maytronics Sponge Climbing Rings (4 Pack) $29.99Maytronics Grey Brush Assembly, DIAG-C.B $39.99Maytronics Guide Wheels (2 Pack) and Pulley Kit $39.99Dolphin Grey Replacement Tracks (2 Pack) $34.99 All Nautilus CC Plus parts →
Clogged filters stop the robot climbing, make it circle and trigger short cycles. Brown or green filter panels that no longer rinse white need replacing.
Worn? Replace it:Maytronics Fine Filter Assembly, M Line $109Ultra-Fine Debris Filter Panels (4 Pack) $49.99 All Nautilus CC Plus parts →
The robot needs at least 3 ft of water, water above 43°F (59°F for wall climbing) and balanced chemistry. Lay out only as much cable as the pool is long.
Power supply will not stay on with the cable disconnected? That is a power supply fault, not the robot: follow the power supply checks and about a replacement under warranty.
Pick your problem
Problem 1 of 5 · 4 fixes
Parts for these fixes:Dolphin Power Supply 180W Weekly Timer $399 All 13 Nautilus CC Plus parts →
Try this first: If the power supply stays on when your Dolphin stops, unplug it, remove the robot from the pool, and inspect the tracks and brushes for debris or damage.
The self-service tool provides troubleshooting and lets you submit a warranty claim for a repair or power supply replacement.
For repair help, including a robot purchased through a local dealer, chat with Poolbots' pool experts. For warranty repairs, Poolbots will point you to Maytronics' service process.
If your Dolphin stops shortly after starting or ends its cleaning cycle early, follow the checks below. A red light on the power supply indicates an error with the robot.
Before turning on your Dolphin: Make sure it is submerged in at least three feet of water.
Check whether the power supply also shuts off. If it turns off as soon as the robot stops, the problem may be with the power supply. Follow the power supply troubleshooting steps.
If the power supply stays on but your Dolphin stops cleaning early, follow these steps:
Unplug the power supply from the electrical outlet. Then take your Dolphin out of the pool.
Turn the robot upside down and rotate the brushes by hand. A small amount of resistance is normal.
Look over the tracks, brushes, and tight spaces around them for anything blocking movement or showing visible damage.
Follow the track-cleaning instructions if you find debris in the tracks.
If debris is caught in the impeller, open the impeller area, clear out the debris, and reassemble it. Use a Phillips-head screwdriver, not a power drill.
Follow the impeller-cleaning instructions for this check.
If your Dolphin has a Power Stream mobility system, it is located on top of the impeller. Inspect the plastic cover around the motor unit and the grilles on the sides of the robot. Clear away any visible debris.
For help with these checks, contact Poolbots' pool experts by live chat or phone.
Try this first: Try a different GFCI outlet you know works. Plug the power supply directly into the outlet without an extension cord.
Use Maytronics' self-service troubleshooting tool to check your Dolphin and start a warranty claim for a repair or replacement power supply.
For repair help, including robots purchased from a local dealer, chat with Poolbots' pool experts. For warranty repairs, Poolbots will point you to Maytronics' service process.
Follow these steps if your power supply stops working, trips the GFCI outlet, or will not turn on.
Try a different GFCI outlet that you have confirmed works. If you are using an extension cord, remove it and plug the power supply directly into the outlet.
If the power supply still will not turn on, continue to Step 2.
Unplug the power supply. Look over the blue cable and the black power supply cord for cuts, kinks, fraying, or other visible damage.
If you find damage, stop and arrange a cable replacement. Start a warranty claim or chat with Poolbots' pool experts for help.
If both cables appear undamaged, continue to Step 3.
This test helps determine whether the problem is with the power supply, the cables, or the Dolphin's motor unit.
This result points away from the power supply. The Dolphin's cable or motor unit may be causing the problem.
An authorized Dolphin technician should diagnose and repair the robot. Submit a repair request or chat with Poolbots' pool experts. For warranty repairs, Poolbots will point you to Maytronics' service process.
If it will not turn on, shuts off right away, or has stopped working altogether, the power supply appears to be the problem. Use Maytronics' self-service tool to start a warranty claim for a replacement power supply.
You can also chat with Poolbots' pool experts about replacement options, including if you purchased the robot from a local dealer.
Maytronics does not repair power supply units.
Check your robot's user manual to confirm which features your model includes.
See the Dolphin app connection troubleshooting guide.
Try this first: Unplug the black cable, disconnect and inspect the blue cable, then plug the power supply into a different outlet. Reconnect the blue cable and try starting the robot.
Use these steps if your corded Dolphin robot will not start cleaning after you turn it on. They also apply if the main LED on an IoT Power Supply is red.
If the power supply itself will not turn on, follow the power supply troubleshooting guide instead.
The Maytronics self-service tool also offers troubleshooting and lets you submit a warranty claim for a repair or power supply.
Unplug the power supply and disconnect the blue cable before inspecting the impeller or tracks.
See the impeller cleaning guide for detailed instructions.
Follow the track cleaning instructions to clear trapped debris.
If your robot is out of warranty, Poolbots sells replacement parts. Confirm the correct part number before ordering. You can use the Maytronics parts reference to check it.
Find more information about your robot's features and functions in its user manual.
For repair help, including robots purchased through a local dealer, contact Poolbots' pool experts by live chat or phone. For warranty repairs, Poolbots will point you to Maytronics' service process.
Try this first: Check your Dolphin model’s user manual or Poolbots product page to confirm which power supply features it supports.
Your Dolphin robot is programmed for the features supported by its specific model. Some optional features may not be available on your robot or its power supply.
Multiple Dolphin models share the same power supply housing. Some support Bluetooth connectivity, while others do not. Matching housings do not mean matching features. The internal functionality can differ by model.
Check your robot’s user manual or its product page on Poolbots to confirm which features are available for your model.
Problem 2 of 5 · 10 fixes
Parts for these fixes:Maytronics Sponge Climbing Rings (4 Pack) $29.99Maytronics Grey Brush Assembly, DIAG-C.B $39.99Maytronics USA Switching 3W Cord $16.1456-Foot Two-Wire Communication Cable With Swivel $229.99Maytronics Guide Wheels (2 Pack) and Pulley Kit $39.99Dolphin Grey Replacement Tracks (2 Pack) $34.99 All 13 Nautilus CC Plus parts →
Try this first: Start with the water temperature. Keep it above 15°C for climbing, while staying within the recommended operating range of 6°C to 35°C.
Work through these checks in order. The Dolphin Tips video shows the troubleshooting process step by step.
The recommended operating range is 6°C to 35°C. Cold water can significantly reduce your Dolphin's ability to climb. For climbing performance, keep the water above 15°C while staying within that operating range.
Make sure your pool chemicals are within their recommended ranges. A pH level that is too high or too low can affect wall climbing.
If your Dolphin offers fast mode or "Floor Only" mode, make sure neither is selected. This check applies only to models that support these settings through the MyDolphin/MyDolphin™ Plus app or the power supply unit.
Debris can obstruct the impeller. Refer to the impeller-cleaning instructions and follow these precautions:
If your Dolphin has an adjustable handle, position it diagonally to help the robot climb.
Make sure there is enough cable in the pool for the robot to climb the walls. Too little cable can pull it back.
To check the amount needed, measure a length of cable that matches your pool's longest dimension. Avoid putting excess cable in the water, since that can lead to tangles.
The right brush depends on your Dolphin model, pool surface and pool slopes.
A combined brush may help if your robot struggles to climb or stay against the pool surface. Before switching, chat with Poolbots' pool experts to confirm compatibility with your model.
If these checks do not resolve the problem, contact Poolbots' pool experts through live chat or phone. For warranty repairs, Poolbots will point you to Maytronics' self-service repair process for sending the robot in for repair.
These links are retained as source references. For help choosing parts or confirming compatibility, use Poolbots' live chat or phone support.
Try this first: If your Dolphin has foam rings on its brushes, place them in the pool water and let them soak so they can absorb water.
Soak foam brush rings. If your Dolphin has brushes with foam rings, put the rings in the water and give them time to soak and absorb water.
Release trapped air. Excess air may be keeping your Dolphin afloat. As you lower it into the water, gently tilt it from left to right or turn it upside down to let the air escape.
Check the salt level. If your pool is treated with salt, make sure the salt (NaCl) level is no higher than 5000 ppm. Too much salt can increase the robot's buoyancy, making it more likely to float.
Try this first: Check the filter bag or cartridges for clogs and clean them thoroughly. Fine particles can block the filters even when they look clean.
Inspect the filter bag or cartridges for clogs. Clean them after every use. A deeper cleaning may also be needed because fine particles can block filters that appear clean. Follow the filter-cleaning instructions.
Test whether the filters need replacement.\n Run your Dolphin in the water for a 10-15 minute test cycle with the filters removed. Only perform this test in a pool with no debris, since debris could damage the robot.
If your Dolphin works properly without the filters, they need to be replaced. For help with replacement parts, contact Poolbots' pool experts by live chat or phone.
Keep algae out of the pool and maintain balanced water chemistry to help your Dolphin clean properly. Use the recommended water parameters shown below:
If your Dolphin gets caught on the drain, follow the drain troubleshooting instructions.
Try this first: Flip your Dolphin over before placing it in the pool to help release trapped air.
Your Dolphin is programmed to do wheelies to help it turn. If it does wheelies while moving forward or backward, there may be a problem. Check the following items in order.
The Dolphin Tips video walks you through troubleshooting.
Air trapped inside the robot can affect its movement. Flip the robot over before placing it in the pool to help the air escape.
Keep your pool chemicals balanced and within their recommended ranges. Proper balance helps the robot work correctly and protects its components over time.
Make sure the blue cable has enough slack and is not pulling on the robot. Measure your pool's longest side, then allow that same length of cable in the water.
Inspect the filters for clogs. Follow the filter-cleaning instructions to clean them.
If your robot has an Ultra-Fine filter, it should look white. If it looks brown or green, clean it with a garden hose at its highest pressure setting. If it still does not look white after cleaning, it likely needs replacement.
See the replacement-parts information, or chat with Poolbots' pool experts for help finding replacement parts.
Check the impeller for trapped debris. See the impeller-cleaning instructions and follow these steps:
Try this first: Try running your Dolphin with the pool filter system off for the entire cleaning cycle to reduce suction from the main drain.
If your Dolphin gets caught on the pool drain and cannot free itself, try these steps in order.
Keep the pool filter system off for your Dolphin's full cleaning cycle. Extra suction from the main drain can hold the robot in place.
Aftermarket drain-assist devices attach to the main drain cover and can help keep your Dolphin from getting stuck. You can find these devices by searching online.
If your Dolphin has an adjustable handle, move it to the farthest slot toward the front. This can help the robot get over the drain.
Try this first: Straighten any twists or bends in the cable. Leave enough length to reach the whole pool, then coil the extra cable on the caddy or lay it beside the pool.
Straighten any twists or bends. Make sure enough cable is available for your Dolphin to reach every part of the pool. Coil any extra cable on the caddy or lay it alongside the pool.
At the beginning of the next cycle, place your Dolphin in the area it usually misses. This can change its initial cleaning route and help it clean more effectively.
Try this first: Remove your Dolphin from the pool and stretch its cable out in the sun for at least 3 hours to help straighten kinks and twists.
Stretch the cable in the sun. Take your Dolphin out of the pool. Stretch the cable out in the sun for at least 3 hours to help remove kinks and twists.
Check the water conditions. After straightening the cable, keep the water temperature above 59°F and pool chemicals within Maytronics' recommended usage range to help prevent tangles. Pool chemical information
Limit the amount of cable you use. Avoiding excess cable is the most important step for preventing tangles. This matters whether your Dolphin has a swivel or not, especially if it does not. Measure out a cable length equal to the longest length of your pool. That is the amount your robot needs.
Position the power supply. Place it near the middle of the pool's longest side, several feet back from the edge. This lets the blue cable enter the water in a straight, relaxed line. It also helps keep tension even as the robot moves and allows the swivel, if equipped, to turn freely.
Loosely coil the extra cable. As you place the robot in the pool, leave the excess blue cable in loose coils at the pool's edge. This helps the cable feed into the water naturally as the cleaner moves.
Wind the cable properly after use. Pay attention to how you wind the cable after each cleaning cycle to help keep it free of tangles.
Check the wheels or tracks. Look for anything blocking their movement. An obstruction can make your Dolphin travel in circles and twist its cable. See how to clean the tracks.
Try this first: If the tracks came off during the first use, try reinstalling them by hand. Tracks can sometimes shift and loosen during shipping.
A new Dolphin’s tracks can shift and loosen during shipping. If they come off when you first use the robot, reinstall them by hand.
Frequent use in a pool with unbalanced chemicals can damage the tracks and leave them slack. Check that your pool chemistry is within Maytronics' recommended ranges shown below.
If the tracks look faded and remain loose and keep slipping off after you reinstall them and check the pool chemistry, replacement is recommended.
See how to reinstall the tracks
For help purchasing replacement tracks from Poolbots, use live chat or call Poolbots' pool experts.
Try this first: Unplug the power supply from the outlet, then turn the robot upside down and look for anything caught in the tracks, brushes, or crevices.
Our playlist of videos on how to clean your robot's tracks
Step 1: Disconnect the power Unplug the power supply from the electrical outlet before inspecting your Dolphin robot.
Step 2: Inspect the tracks and brushes Turn the robot upside down. Look over the tracks, brushes, and small crevices for anything caught inside or any visible damage.
Step 3: Remove the obstruction if you can reach it If you spot something stuck, try to reach it and remove it if possible.
Try this first: Gently guide your Dolphin to the pool edge with the cable, then lift it by the handle. Tilt it as you set it on the edge to drain. Never use the cable to lift it out.
Start by checking how you take your Dolphin out of the pool. Gently draw it toward you with the cable until it reaches the pool edge. Then use the handle to lift it out. Do not lift the robot out of the water by its cable.
As you set the robot on the pool edge, tilt it so the water can drain. If debris keeps dropping into the pool, try taking the robot out facedown or upside down.
If that does not solve the problem, work through these checks:
Inspect the filter and the non-return debris flap or bag at its bottom. The flap or bag should be seated correctly and working as it should.
Very fine particles can escape during removal. Debris can also fall back into the pool when the filter holds a large amount of it. Try Ultra-Fine filters if they are available for your robot. Clean the filters each time you take the robot out of the pool.
Inspect the intake opening and its non-return debris flap. Check that the non-return bag or flap at the bottom of the filter basket or cartridges is properly seated, with nothing blocking it.
Look for debris in the impeller and clear any you find.
Take out the filter basket. Inspect the four springs at the bottom of the unit, underneath the basket, and clear any debris clogging them.
Turn the robot upside down. Look behind the rear wheels and confirm that the black rubber rapid drain flap is in place.
For EON 100 models with a monoblock filter basket, check that the basket is installed with the filter lid latch pointing toward the impeller.
Problem 3 of 5 · 4 fixes
Parts for these fixes:Maytronics Fine Filter Assembly, M Line $109Ultra-Fine Debris Filter Panels (4 Pack) $49.99Fine Debris Filter Panels (4 Pack) $35.99 All 13 Nautilus CC Plus parts →
Try this first: Unplug the power supply, clean the filter, and check for trapped debris before starting another cleaning cycle.
If your Dolphin is leaving debris behind or missing areas it used to clean, work through these checks.
Check your pool water against these ranges:
Keeping the water within these ranges supports cleaning performance and helps protect the robot's lifespan. Weather, swimmers' body chemistry, and other factors can change water chemistry, so test it regularly.
Water temperature should be between 43°F and 95°F. If the robot has trouble climbing, check that the temperature is above 59°F. Colder water can make climbing harder.
For a spot the robot repeatedly misses, place it in that area at the beginning of the cleaning cycle.
If it gets stuck in the deep end, replacing the back brush with a Combined Brush or Wonder Brush may help. This option depends on the model. Chat with Poolbots' pool experts or call to confirm whether either brush is suitable for your robot before making a change.
The type of debris determines which filter to use.
For small particles such as sand and dirt, use ultra-fine filters. If your model did not include them, they are available separately. Poolbots sells replacement filters, and Poolbots' pool experts can help you select filters for your model.
For larger debris, including leaves and other tree foliage, use fine (net) filters.
For sticky, algae-like debris, ask Poolbots' pool experts about having a pool technician assess it and recommend the appropriate treatment.
After a chemical shock treatment, keep the robot out of the pool for at least 24 hours. Before putting it back in, also confirm that the chemical levels have returned to normal.
For a heavily littered pool, run consecutive cleaning cycles and clean the filter after every cycle.
Clean the filter after each cleaning cycle to help prevent clogs. Follow the filter cleaning instructions.
Use fine filter panels for leaves, bugs, and other large debris. Choose ultra-fine filter panels for dust, dirt, and sand.
Check that the filters are not clogged and that debris is not trapped elsewhere in the robot. Blockages can reduce suction and keep the robot from picking up debris properly.
Replace the filter panels if they no longer rinse back to white or if debris remains stuck to them. Poolbots' pool experts can help you choose replacement filters.
See the impeller cleaning instructions.
Inspect the non-return valve, which is the opening at the bottom of the filter, or the small black pouch attached to it. Clear away any trapped debris.
If your model has a rubber rapid drain flap on the back, check that it is securely in place.
Inspect the PVC brushes for tears, wear, or other visible damage. Replace worn or damaged PVC brushes.
If the brushes have white climbing rings, check that the rings are still white and have not flattened or become damaged. Replace climbing rings that show wear or damage.
Check that the tracks fit snugly and have no damage or discoloration. Replace loose or discolored tracks, and check that the pool chemistry is within the ranges listed above.
Poolbots sells replacement parts. Contact Poolbots' pool experts by live chat or phone for help selecting brushes, climbing rings, or tracks for your robot.
Dolphin robots are not designed to clean steps, stairs, or ledges. Brush debris from the steps down onto the pool floor so the robot can collect it.
The robot needs to be submerged in at least 35 inches of water to work properly.
If debris collects in the seam of a steep slope, brush it onto a flat surface where the robot can reach it.
Put enough blue cable in the water for the robot to reach every part of the pool. The robot's cable must also be long enough to cover the entire pool.
Measure between the pool's two farthest corners to estimate how much blue cable is needed. For a pool longer than 30 feet, use a robot with a 60-foot cable.
Check that your robot's brush type is suitable for your pool's coating.
A PVC brush is the best match for PVC, concrete tile, concrete, or gunite coatings.
A Combined brush is the best match for PVC, rough ceramics, fiberglass, or mosaic coatings. Remove the nylon before use.
A Wonder brush is the best match for smooth ceramic, stainless steel, or glass coatings.
For a different problem, browse the Dolphin troubleshooting FAQs.
Try this first: Remove the filter basket or panels, rinse off debris with a garden hose, and put them back in your Dolphin. They do not need to dry before reinstallation.
Clean your Dolphin's filters after every cycle to help them last longer and keep your robot cleaning effectively.
Watch this video for an overview of filter care.
Step 1: Remove the filters Take the filter basket or panels out of your Dolphin.
Step 2: Rinse away debris Wash away the collected debris with a garden hose or a high-pressure stream of water.
Step 3: Reinstall the filters Put the filters back into the robot. You can reinstall them while they are wet.
Ultra-fine filters can hold tiny particles, including sand and dust, even when they look clean. Check their color after rinsing. If they no longer rinse back to white, they are clogged, and replacement is recommended.
For replacement filters or help choosing them, contact Poolbots' pool experts through live chat or by phone.
View instructions for replacing filter panels
Clean filters help your Dolphin clean the pool more effectively.
Bag filters can go in a washing machine at 30°C. Air drying is recommended afterward.
Filter cartridge panels can be washed in a dishwasher set to 30°C.
Learn how the filter types differ
Try this first: Check the impeller for obstructions, thoroughly clean the filters, then reset the power supply using the instructions below.
On an IoT power supply, either or both of these signals indicate a full filter:
The filter can look clean but still be clogged. Small particles can dry on the filter material and block it.
Check the impeller for anything blocking it and clear any obstructions.
Give the filters a thorough cleaning, even if they do not look dirty.
Clean the filter bag or cartridges after every cleaning cycle. A deeper cleaning may also be needed:
Step 3: Reset the power supply\n Once the impeller and filter maintenance is complete, follow the reset method for your power supply:
Try this first: First, unplug the power supply from the outlet. Check the impeller for trapped debris. If you need to open it, use a Phillips-head screwdriver, never a power drill.
Follow these steps to clear a clogged impeller on your corded Dolphin robot.
Step 1: Unplug the power supply Make sure the power supply is disconnected from the electrical outlet before you begin.
Step 2: Clear the impeller If you see debris trapped in the impeller, open it, remove the debris, and put it back together. Use a Phillips-head screwdriver, never a power drill.
Step 3: Check the side grilles If your model has grilles on its sides, look for visible debris there too.
Find your model below and watch the matching short video for impeller cleaning instructions.
S50 (Cayman, T15, T25, Active 10, Escape, Encore, E20, E25)
S100 (Advantage, Proteus DX3, Saturn, Echo, Nautilus CC, Active 15, Escape)
S200 (E30, Advantage Ultra, Active 20, Quantum, T30, Proteus DX4)
S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i)
S400 (E50i, Active 50, Explorer E50)
M600 (Active 60, E60i, Premium 60)
M700 (Explorer E70)
Nautilus CC Plus (DX3)
M400 (Sigma/Nautilus CC Supreme)
For Liberty, follow the separate cleaning guide: How to clean the Liberty impeller
You can also find impeller cleaning instructions for your Dolphin model on the online manual website.
Problem 4 of 5 · 5 fixes
Try this first: Stand near the power supply, close and reopen MyDolphin Plus, and retry setup with Bluetooth on and a 2.4 GHz Wi-Fi signal of at least 60%.
MyDolphin Plus from Maytronics uses a cloud connection to let you control your Dolphin in real time, wherever you are and whenever you need to.
Watch this quick video for help with your first connection, or follow the steps below.
If your network cannot meet these requirements, you can use a Bluetooth-only connection instead.
For Android, turn on GPS and location services.
For iOS 13 only, give MyDolphin Plus permission to use Bluetooth and location services while the app is running.
Once pairing is complete, you can name your Dolphin, register its warranty, and use the app's features.
Setup has three connection stages. The percentage shown on the loading screen can help identify where the connection is failing.
After Bluetooth pairing, your phone sends the Wi-Fi information to the power supply. A stall here can mean that the connection dropped or the information did not transfer correctly.
The power supply checks the Wi-Fi requirements, including the 2.4 GHz frequency, as it connects to the router. This stage can take up to 2 minutes.
A failure at this stage points to a problem with the cloud connection.
MyDolphin Plus supports WPA/WPA2-Personal and WPA2/WPA3-Personal.
Buying a Wi-Fi-compatible power supply will not make a non-Wi-Fi Dolphin compatible with MyDolphin Plus.
Check the user manual to confirm whether your Dolphin supports the app.
Try this first: First, update MyDolphin Plus if needed and confirm your phone is on the same Wi-Fi network the app is trying to use.
Connection problems can have several causes. Follow the section that matches your app and what changed before the problem started.
If a new or replacement power supply cannot find the robot, follow these steps:
A weak Wi-Fi signal around the pool may cause the connection to drop. Try these options:
For additional Wi-Fi troubleshooting, see the General Wi-Fi Connectivity Guide.
If a message says MyDolphinPlus is incompatible with your robot model, download the MyDolphin App or check whether your model supports an app in the User Manual here.
The power supply may be too far from your smart device. Bluetooth® may also be turned off or not working properly.
Try this first: Try fresh batteries first, then test the remote within 3 meters of the robot's power supply.
For instructions on using the Basic Remote, download its manual:
Remote Basic Manual 1-5.pdf
Try this first: First, turn on the Dolphin power supply, enable Bluetooth and GPS on your phone, and open MyDolphin within 3 feet of the power supply.
The MyDolphin™ app lets you control your Dolphin pool robot remotely over Bluetooth®. Available features depend on your model and may include cleaning programs, a weekly timer, and manual control. Check your robot's user manual to see which features it includes.
Applies to: Dolphin Proteus DX3, Dolphin ADVANTAGE ULTRA, Dolphin S200, Dolphin Quantum, Dolphin Active 20, Dolphin Proteus DX4, Dolphin Premium 30, Dolphin T35, Dolphin Explorer E30 WiFi, Dolphin T60.
Make sure your phone meets these requirements:
Pairing can take up to 2 minutes, depending on the strength of your 3G or 4G signal. Give the app time to finish.
If you have connected successfully before but now have trouble, follow the guide for restoring an app connection.
Try this first: Check that the blue cable is firmly plugged in, and inspect the cable for damage.
This error in the My Dolphin Plus App means the blue cable is having trouble carrying the app's commands from the power supply to your Dolphin robot.
Confirm that the blue cable is firmly plugged in. Inspect the cable for damage.
Put the robot in the pool. In the app, try Manual Drive or select another cleaning mode, if available.
If the Communication Error appears again, the communication problem is still present and the robot needs repair.
For repair help, chat with Poolbots' pool experts, including if you purchased your robot through a local dealer. For warranty repairs, Poolbots will point you to Maytronics' service process.
You can submit a warranty claim to send your robot to a Maytronics service center for repair.
Problem 5 of 5 · 2 fixes
Parts for these fixes:Maytronics USA Switching 3W Cord $16.1456-Foot Two-Wire Communication Cable With Swivel $229.99Maytronics Fine Filter Assembly, M Line $109Ultra-Fine Debris Filter Panels (4 Pack) $49.99Fine Debris Filter Panels (4 Pack) $35.99Maytronics Sponge Climbing Rings (4 Pack) $29.99 All 13 Nautilus CC Plus parts →
Try this first: Start by watching the video below for guidance on installing the cable float.
The video below demonstrates how to install the float on the blue cable.
Applies to these models:
Try this first: Before removing a brush, unplug the power supply and find the matching model and brush position below.
Disconnect the power supply from the electrical outlet before starting. Find the front, middle, or rear brush section below, then follow the video and instructions for your model.
For help choosing a replacement brush, contact Poolbots' pool experts by live chat or phone.
Replacement front brush: 9995544-ASSY.
S100 (Advantage, Proteus DX3, Saturn, Echo, Nautilus CC, Active 15, Cayman, Escape, Explorer E20)
S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i)
S400 (E50i, Active 50, Explorer E50)
Follow the video for the front-brush replacement procedure.
Follow the video for the front-brush replacement procedure.
Replacement middle brush: 9995541-R1.
This middle-brush procedure applies to Sigma produced in 2026 or later.
Replacement rear brush: 99955380-ASSY.
S300 (E35/E35i, Proteus DX5i, Active 30, T35/T45, Premium 40, Explorer E30, E40i, Active 30i, T55i)
S400 (E50i, Active 50, Explorer E50)
Replacement rear brush: 99955380-ASSY.
Replacement brush assembly: 99955340-ASSY.
Replacement rear brush: 99955340-ASSY.
Follow the video for the rear-brush replacement procedure.
Follow the video for the rear-brush replacement procedure.
From the user manual
The troubleshooting table printed in the Nautilus CC Plus manual, one card per symptom. A part named here is in the parts list below.
Replacement parts
Worn filters, brushes and tracks cause most of the problems above. These are the parts Maytronics lists for model 99996403-PC; each one opens with what it does and when to replace it.
Downloads
Beyond fixes
Setup, care, storage and the app: 37 more answers that apply to this robot.
Still stuck?
If the checks above did not fix it, the robot may need a repair. Under warranty, Maytronics handles power supplies by replacement and robots through its repair centers; have the serial number from the label under the handle ready.
Maytronics' own tools: self-service diagnostic and repair request · register your robot.
