How durable is the Maytronic Dolphin M400 robot?


Active member
May 15, 2018
Just got my M400 and used it for the first time. Very impressed. Cleaned very well, easy to use, etc. I made sure to properly clean it out after use, coil everything neatly, and I have it on a caddy and inside a storage bin when not in use to protect it from the elements. My question is, how durable are these things in the long run? How do the parts hold up against chemically treated water over time? How durable is the entire unit, say if it was accidentally dropped or fell off the caddy? Just curious, cause it seems pretty rugged, but don't want to take any chances, considering the price tag on these things.


Well-known member
Aug 19, 2013
I have yet to drop any robot I've owned, but I guess that would depend on the surface it was dropped onto and the height. As for how durable, hard to predict. My old Dolphin Diagnostic was over 15 years old. It runs fine but it's on its 3rd power supply (the old ones were awful). I've had my S300 for 4 years and use it for over 100 cycles a season (in Chicago, so seasons are limited). Still functions like it did on day 1. Th eshell and teh submerged sections of cord are bleached out, but that's purely cosmetic. If the iO comes out next year I might bite just for the novelty, but I'm very happy with my S300.

As a PS, just like with new babies, I was very disciplined with retrieving and cleaning my S300 for the first season but I've gotten lazier and sloppier over the seasons, leaving it in for days at a time with no ill effects.


Active member
May 4, 2014
Antioch, Ca
I got 5 trouble-free years to the day out of my Oasis z5, which is essentially the same as your M400. I didn't baby it either. Saw a lot of sun, a lot of leaves, and a lot of action. Only reason I didn't pony up for another, is because I'm partial to the new filter basket design, so I went with the cheaper Active 20 instead. Not expecting 5 years again, but hoping to at least approach it.