Are Dolphins terrible or am I doing it wrong?

[Drew80]

I'm on my 4th Dolphin. The first one worked fine but I sold it because the basket was too small. I then bought a Triton PS that didn't work at all, so I got a warranty replacement. The second one worked for a few months, then started turning itself off after about 10 seconds - another warranty replacement. The replacement was an S200, which I still have. The last 2 Dolphins, including the current one, have had the same issue. They would turn on but never complete a cycle. As of this morning, my S200 will turn on and run for about 10 seconds then turn off.

I just opened up the unit to make sure nothing is blocking the impeller or water flow - everything looks fine. Starts up as expected but quits after about 10 seconds, and that's happening consistently.

At some point you have to question whether the problem is you. Am I doing something wrong or are these units just awful?

 

[Kaptain]

From what I have learned they go through a self test when you power them on, if something fails it shuts down. Visually you will see the robot move forward, backwards, forward again, then shut down. This is usually caused by hair and Crud wrapped around that impeller. But like you said you checked that.
I had one robot that did this and found that the motor that spins the impeller was going bad. It just did not spin enough. I believe it was caused by a bad seal that took out the motor bearings.
There is or was a guy on eBay that was selling replacement bearings and seals. I bought two sets so I could fix mine but ended out swapping it for a good motor.

I fixed several of these last summer and if I remember correctly all of the similar models that Dolphin (Maytronics) made have the same guts. It's the power unit that makes them smart (bluetooth) or not.
If you are comfortable tearing it apart, I'd inspect that motor.

 

[Kaptain]

From what I have learned they go through a self test when you power them on, if something fails it shuts down. Visually you will see the robot move forward, backwards, forward again, then shut down. This is usually caused by hair and Crud wrapped around that impeller. But like you said you checked that.
I had one robot that did this and found that the motor that spins the impeller was going bad. It just did not spin enough. I believe it was caused by a bad seal that took out the motor bearings.
There is or was a guy on eBay that was selling replacement bearings and seals. I bought two sets so I could fix mine but ended out swapping it for a good motor.

I fixed several of these last summer and if I remember correctly all of the similar models that Dolphin (Maytronics) made have the same guts. It's the power unit that makes them smart (bluetooth) or not.
If you are comfortable tearing it apart, I'd inspect that motor.

He's still selling them on eBay. I am almost positive that's what you will need to fix this. If this repair is something you are not comfortable performing, I may be able to help.

 

[Drew80]

@Kaptain I opened it up and turned it on. The wheels and treads turn in both directions, as you said, and the impeller doesn't spin at all. Should that spin as part of the self test?

I'm very comfortable with repairs, and the internals on these are pretty simple. Do you have a link handy for the guy on Ebay?

 

[Kaptain]

@Kaptain I opened it up and turned it on. The wheels and treads turn in both directions, as you said, and the impeller doesn't spin at all. Should that spin as part of the self test?

I'm very comfortable with repairs, and the internals on these are pretty simple. Do you have a link handy for the guy on Ebay?

FOR MAYTRONICS LINIX DOLPHIN IMPELLER MOTOR PUMP RERAIR KIT BEARING BRUSHES SEAL | eBay

NOTE: THIS IS THE REBUILD KIT FOR IMPELLER MOTORS ONLY! DOES YOU POOL DOLPHIN CLEANER DUE A SELF TEST AND STOP OR RUN FOR A LITTLE WHILE AND STOP. THE MOST COMMON PROBLEM IS THIS MOTOR AND IT SUPER EASY TO FIX YOUR SELF.

ebay.us

 

[Jimrahbe]

Drew,

Yes, part of the self test is to run the suction motor at different speeds..

You have to remove the impeller and look at the motor shaft.. It can get string-like material wrapped around it..

I have given up on the Dolphins...

Jim R.

 

[Kaptain]

If your robot isn't that old and it decent shape, fix it. Bit if your cord is not great and the unit is showing wear from use maybe it's time.
I have lots of good used parts if you need anything

 

[Bperry]

Also make sure it’s in the water when doing the tests. Maybe obvious but figured it’s worth a shot just in case.

 

[Jimrahbe]

Drew,

The tests can be done out of the water, with the robot on its back... but... it will often pass out of the water tests, yet fail when in the water..

So my initial tests would be out of the water.. If it does not pass, it will not pass in the water.. It it passes out of the water, then put it in the pool and try it again.

Thanks,

Jim R.

 

[Drew80]

The impeller isn't spinning at all during the self test. I can spin it manually very easily, so my initial guess would be an electrical problem.

 

[Drew80]

If your robot isn't that old and it decent shape, fix it. Bit if your cord is not great and the unit is showing wear from use maybe it's time.
I have lots of good used parts if you need anything

This thing is less than a year old, and I store it in a deck box when I'm not using it. So it's practically brand new. And the third time I've had a Dolphin do this. Frustrating.

 

[SJPoe]

It has been said on this forum a number of times that these robots have become practically throw-away items. I'd agree if they weren't the best part of $1000+

Of course, the cynic in me thinks that if you are the #1 maker of these devices, and you've been making them for 40+ years, and you're still running into reliability issues....either you really suck at what you do, or you're deliberately building in obsolescence to keep your revenue stream going.

 

[Newdude]

..either you really suck at what you do, or you're deliberately building in obsolescence to keep your revenue stream going.

Or they proved during the shortages that terrible quality control would not affect revenue and customers would still buy several in a row, like OP.

 

[SJPoe]

Or they proved during the shortages that terrible quality control would not affect revenue and customers would still buy several in a row, like OP.

Eventually though, it does. I did not buy a new Maytronics model, I chose one from their competition. We're also seeing a lot of new entrants into the market, which we can only hope will spur all of them to raise their game somewhat.

Hey....we can hope anyway...

 

[derek_from_maytronics]

Sorry you’ve had such a rough run with your units. The issue where the robot starts then stops after ~10 seconds is often related to a sensor or blockage.

Before requesting service, try these steps:

1. Don’t use an extension cord.
2. Unplug everything and inspect the blue cable and prongs.
3. Clean filters, impeller (careful—blades are sharp), and intakes.
4. Spin brushes/tracks manually – should rotate freely.
5. Test the unit upside down, plugged in outside the pool – it should rotate briefly, then stop.
6. Let it sit unplugged 15 sec, then try again in water.

Video for S200-type models:

If it still doesn’t work, definitely reach out to customer support—it may be a hardware fault.

 

[Kaptain]

To me it's strange. I got my first Pentair Prowler in 2017 and it ran great until the summer of 2024; back and forth problem. I tore into it and found out it was the motor driving the impeller which is typical. In the summer my Prowler is 80% in the pool 20% on the deck, and 100% inside fall/winter. I have no clue how I had so many trouble free years.
Back to 2024. Talking to the pool store owner about my issue he said that "it's common and time to buy a new one" which is why he does not sell them anymore "I have a pile of warranty returns in the back to prove it." I asked if I could salvage parts from them to fix mine and he told me to take them.
I will try to recall what I found: Out of the 7 I brought home 2 had bad cords, I believe 3 had bad power units, and the last 2 were a combination of bad cords and water damaged impeller motors. I ended up fixing mine, giving it to a buddy and keeping the best one for myself. I also had more power units than bots which leads me to believe they can be troublesome.
If I learned anything last summer from tearing 8 of these apart it is this:

• The cords are expensive and the swivel will fail. Maybe cleaning and lubing it yearly will extend its life.
• Impeller motor will eventually happen, but as I mentioned above it's fixable.
• The power box is also likely to fail but easily diagnosed. It outputs 30v. Keep this out of the sun!!!!
• The guts in the bot is the same across all 3 models with the exception of the 920. The mainboard is a different rev that does not have blue tooth. Power units are different as well.
• Keep the impeller free of debris; there are youtube videos on this.

I purchased two motor rebuild kits last summer to fix what I have; still in the box. The repair doesn't look too bad but does require some soldering and a small bearing puller. I imagine this is where some folks will tap out and buy a new one. With what I have piled up in my basement I am confident that I will run mine for another decade. I just snagged up a brand-new cord on marketplace last weekend for 85 bucks.

@Drew80 I believe the unit I kept out of the 7 was less than 1 year old. Not a scratch on it and nothing was faded from being in water. Not sure why it was warrantied, I tossed it in my pool plugged it in and off it went...

 

[Newdude]

Eventually though, it does. I did not buy a new Maytronics model, I chose one from their competition

Agreed. I stayed on the fence when they started dropping like flies. Now that the EVOs are holding up well, my finances have changed.

 

[Drew80]

To me it's strange. I got my first Pentair Prowler in 2017 and it ran great until the summer of 2024; back and forth problem. I tore into it and found out it was the motor driving the impeller which is typical. In the summer my Prowler is 80% in the pool 20% on the deck, and 100% inside fall/winter. I have no clue how I had so many trouble free years.
Back to 2024. Talking to the pool store owner about my issue he said that "it's common and time to buy a new one" which is why he does not sell them anymore "I have a pile of warranty returns in the back to prove it." I asked if I could salvage parts from them to fix mine and he told me to take them.
I will try to recall what I found: Out of the 7 I brought home 2 had bad cords, I believe 3 had bad power units, and the last 2 were a combination of bad cords and water damaged impeller motors. I ended up fixing mine, giving it to a buddy and keeping the best one for myself. I also had more power units than bots which leads me to believe they can be troublesome.
If I learned anything last summer from tearing 8 of these apart it is this:

• The cords are expensive and the swivel will fail. Maybe cleaning and lubing it yearly will extend its life.
• Impeller motor will eventually happen, but as I mentioned above it's fixable.
• The power box is also likely to fail but easily diagnosed. It outputs 30v. Keep this out of the sun!!!!
• The guts in the bot is the same across all 3 models with the exception of the 920. The mainboard is a different rev that does not have blue tooth. Power units are different as well.
• Keep the impeller free of debris; there are youtube videos on this.

I purchased two motor rebuild kits last summer to fix what I have; still in the box. The repair doesn't look too bad but does require some soldering and a small bearing puller. I imagine this is where some folks will tap out and buy a new one. With what I have piled up in my basement I am confident that I will run mine for another decade. I just snagged up a brand-new cord on marketplace last weekend for 85 bucks.

@Drew80 I believe the unit I kept out of the 7 was less than 1 year old. Not a scratch on it and nothing was faded from being in water. Not sure why it was warrantied, I tossed it in my pool plugged it in and off it went...

@Kaptain, I'm confused. Are we talking about a Pentair unit or a Dolphin?

 

[Kaptain]

@Kaptain, I'm confused. Are we talking about a Pentair unit or a Dolphin?

They are the same. Both made by maytronics

 

[Drew80]

@Kaptain aha! I wasn't aware Maytronics made anything for Pentair