From the start, Dreame’s Z1 Pro robotic pool cleaner certainly seems to check off all the boxes. Its features list touts just about everything: The ability to clean floor, walls, and waterline. Big, dual, front-mounted brushes. Three hours of running time. Mobile app support. And a remote control in the box. I’m not sure what the touted “Triple Surround Fusion Perception System” is, but that sounds good, too.

Specifications

I’ll start with what I liked the most: After unboxing, I discovered that the 27-pound robot offers one of the most convenient charging systems I’ve seen to date, thanks to a magnetic charging mechanism that simply snaps onto the device’s chassis, with no plugs or rubber gaskets involved—and no need to hoist the robot onto a bulky charging station, either. There’s even a small microfiber cloth attached to the end of the charging cable for wiping off any moisture on the contacts; that’s a thoughtful touch.

Dreame’s mobile app is maybe its coolest feature, the first I’ve seen that can visually map the pool after a run.

The Dreame hardware looks tough, but it’s not garish: a silver-and-black device with large-wheeled treads and promised support for scrubbing up to 2,160 square feet of pool surface area. The included light-pulse remote charges via USB-C, and even the remote’s color and shape fit the Z1 Pro’s design theme.

LEDs on top of the Z1 Pro provide a handy indication of battery-charging status and operating mode (floor, walls, waterline, or everything, accessed via a single selector button). A top-mounted hatch gives you access to a single-piece filter basket that pops out easily. The bottom of the filter opens on a hinge to allow for easy cleaning after a run.

Dreame’s mobile app is maybe its coolest feature, the first I’ve seen that can visually map the pool after a run. With support for both Bluetooth and Wi-Fi, the app also makes it easy to get a quick look at the robot’s status (provided it is turned on and out of the water), set cleaning settings remotely, and to configure a routine cleaning schedule if you leave your robot in the pool for multiple days at a time. (The non-Pro Dreame Z1 loses a few features, including the remote, and costs $200 less.)

So, there’s plenty to like here, which was all the more saddening when my initial experience with the device didn’t go very well.

Performance

My first issue involved the remote control. Out of the box, it didn’t work at all, unable to turn on. Some troubleshooting with Dreame ultimately ended with the company sending me a new one altogether. The new remote did work, but not overly well. A powerful green light must be aimed fairly precisely at a sensor on top of the robot, with pulses directing the robot to pause/restart its task, clean around a certain spot, or return to the surface for retrieval.

But getting the robot to respond to any of these commands was an exercise in both frustration and trial and error, often requiring up to a minute of repeatedly stabbing at buttons, waving the remote around, and hoping something would finally stick.

The good news was that eventually, it usually would, though I ultimately found the remote useful only for telling it to climb to the waterline so I could retrieve it from the pool. It’s just too erratic to use for much else.

My next issue with the Z1 Pro was its initially poor cleaning quality. As I do with all robotic pool cleaners I test, I put the Z1 Pro to work in both organic and synthetic conditions to gauge its performance. After a particularly big storm one night, I woke to find the perfect testing conditions in a pool full of debris. I dropped the Z1 Pro in the pool and watched it get to work. Three hours later, I retrieved the robot to find its filter basket less than half full, and the pool looking like next to no cleaning at all had occurred. (I then dropped in another robot, which took care of things much more effectively.)

I saw similar results with synthetic leaves scattered in the pool: The Z1 Pro was only able to scoop up about two-thirds of the leaves, leaving the rest behind and large areas of the pool clearly untouched. That’s about the worst performance I’ve ever seen in a premium-priced pool robot like this one.

A fortuitous firmware update

Fortunately, Dreame pushed a firmware update during my testing, and after a total of six complete cleaning runs (plus several shorter sessions), I was finally able to see performance improve significantly. Eventually I was able to achieve a cleaning rate of about 90 percent. That’s good but not great, and it still left behind visible debris even on its best days, particularly on and around steps.

Observing the Dreame in action reveals a little about what might be going on, as operations didn’t always make a lot of sense. At one point, about halfway through the run, I found the robot stopped in the middle of the pool, spinning around and around in one spot for nearly 10 minutes. Was it mapping the walls? Pondering the future? Plotting against me? Eventually it did at least get back to work, finishing the rest of the cleaning task without incident. That said, the robot is one of the slowest—if not the absolute slowest—I’ve ever seen, literally crawling across the floor of the pool at a turtle’s pace. Its lack of speed may be a contributing issue to its performance, as debris is always moving in a pool.

When finished, the robot climbs to the waterline and waits for retrieval (still chugging away to keep itself moored in place, as it can’t float otherwise), but only for five minutes, after which it sinks back to the bottom and will have to be retrieved via the included hook or via remote control. If you want to grab it when it’s docked, keep a close eye on your mobile app notifications.

The Dreame app was surprisingly successful at mapping my pool, providing a reasonable facsimile of what my L-shaped pool looks like, at least once. Again, this was the first among the pool robots I’ve tested over the years to do this. But subsequent runs weren’t as solid, leaving me with a map that looked more like a dunce cap.

This review is part of TechHive’s in-depth coverage of the best robotic pool cleaners.

The report issued at the end of each run was usually accurate, though again, not always: Once I received a note that a near-two-hour run had cleaned just 3 square meters of the pool. Other odd errors, like a mysterious “charging error” in the log while the unit was 100-percent charged, defied explanation.

Should you buy the Dreame Z1 Pro?

At $1,099, the Dreame Z1 Pro has a premium price, and consumers would be well justified to demand the highest tier of performance from it. Some of its features are extremely compelling, especially its app.

But to merit a wholesale recommendation, I’d need to see another step up in cleaning performance. Might another firmware update deliver it?

Author: Christopher Null, Contributor, PCWorld