Introduction
Hello everyone,
To start this review as transparently as possible: Zemismart contacted me and asked whether I would be interested in testing some of their devices with Homey. They mentioned that my experience with Matter devices, Homey device behavior, and capability mapping could be useful for this kind of real-world feedback.
I agreed under the condition that my review would remain completely independent and honest. This means that I will point out the positive aspects, but also the flaws and limitations I found during testing.
Zemismart provided me with the three devices free of charge, but this does not influence my opinion or the content of this review.
There are definitely some good things to report, but also some important issues. I will also end this review with a small wishlist of improvements that, in my opinion, could make these devices much more useful in Homey.
Build quality of the devices
The devices are made of plastic. While they obviously do not have the premium aluminium finish of some high-end products, they do not feel cheap either. Considering the price range and the type of device, the overall finish is very well done.
At first glance, the front looks like one large display area that is nicely integrated into the switch. Technically, however, it is not one full-size screen. On the 4-button model, it consists of four small display areas, each providing one line of text. On the 1-button and 2-button models, the number of display areas matches the number of buttons.
Most of the time, the display is off and appears black. As soon as you approach the switch, the display turns on automatically. This gives the device a clean and modern look when it is idle, while still making the labels visible when needed.
The buttons themselves have a clear and audible click point. They feel precise enough and give good tactile feedback when pressed.
Installation and electrical safety
I was told that the devices are CE certified. However, on the devices I received, I was not able to find a visible CE marking on the device housing itself. This does not automatically mean that the product is not compliant, but from a user and installer perspective I would clearly prefer the conformity marking to be visible and easy to verify.
Another important point is the maximum load rating. In many European installations, lighting circuits are protected by a 10 A circuit breaker, which corresponds to roughly 2,300 W at 230 V. The ZM208-4 is rated at 4 Ă— 400 W maximum, while the ZM208-1 and ZM208-2 are rated at 600 W per gang.
This does not necessarily make the device unusable, but it is a serious limitation that must be respected during installation. The circuit breaker cannot be relied on to protect the relay contacts from overload, because the relay rating is much lower than the rating of a typical lighting circuit. In practice, this means that the connected load must be carefully checked and kept well below the device limit. Otherwise, the relay could be overloaded before the circuit breaker reacts.
The terminal design is another weak point. (see red square on first photo) The terminals use simple screws that press directly onto the conductor. This may work with solid copper wires, but it is not friendly to flexible stranded wires. In my test, this type of terminal tended to twist and damage flexible conductors. I would strongly prefer a more modern terminal design with a pressure plate or cage clamp, where the screw lowers a clamping plate instead of pressing directly onto the wire. Even small and inexpensive devices such as Shelly modules use this kind of terminal design.
The dimensions of the electrical block are also problematic for standard European round wall boxes. Although these boxes are often called 68 mm boxes, the usable internal diameter is usually much smaller, around 56 mm. This type of wall box is common in many European countries, including Luxembourg, Germany, France, Belgium, the Netherlands, and others.
The ZM208 electrical block does not fit into these standard round boxes. In addition, the fixing screws are spaced at around 80 mm, while these wall boxes typically use a 60 mm screw distance. This means that the device cannot be mounted directly into such boxes. To test the devices I had to print on wall boxes with PLA FR (self extinguishing) to install the device. Not so nice but functional (see photos)
Another concern is the position of the fixing screws (see blue squares on first photo). They are located at the top and bottom of the electrical block, which is exactly where cables often enter the wall box in many installations. Even if the block could physically be inserted into the box, there would be a risk that the fixing screws could interfere with or damage the cables.
For these reasons, I see the installation design as one of the weakest points of the device, at least for the type of wall boxes and wiring commonly used in my region.
Pairing and configuring the device
Since the ZM208 is a Matter device, I first paired it with Homey in the standard Matter way: adding a new device, scanning the Matter QR code, and following the Homey pairing dialog. This part worked flawlessly. The devices were recognized immediately and paired without any issues. Each physical button is exposed in Homey as a separate button. In practice, this means that the 4-button model appears as four individual buttons in Homey.
For basic use in Homey, no Zemismart Homey app is required. The devices work directly via Matter.
However, if you want to change the labels shown on the built-in displays, you need to install the Zemismart app on your phone and pair the devices with that app as well. This also requires creating a Zemismart account. For me, this is a negative point, because the display labels cannot be configured locally without using a cloud-based service.
The Zemismart app also still has some translation issues. During setup, I was shown an input field with a Chinese label. I guessed that it was asking for my email address, and that turned out to be correct.
After installing and configuring the app, the instructions provided for pairing the device did not work for me. The leaflet suggests using the “+” button, but this led me to an automatic device discovery mode that did not find the device. At this point, I think many regular users would probably give up or even return the product.
With some Matter experience, I found the correct way to proceed. I went back to the device settings in Homey and selected “Share Matter Device”. Then, in the Zemismart app, I went back to the discovery screen and used the small scanner-like button. Since I know that shared Matter codes are not the same as the original QR code on the device, I selected the numerical code option and pasted the code generated by Homey.
This finally worked, and I was able to add the devices to the Zemismart app and configure the display labels.
Flows
In Homey, each button provides four Flow trigger cards:
- Turned on
- Turned off
- Turned on for x seconds
- Turned off for x seconds
In my test, these Flow cards worked as expected. Button presses were detected correctly, and the corresponding Flows were triggered reliably.
This is a positive point, because it makes the devices useful not only as physical switches, but also as practical input devices for Homey automations.
Edit:
The device also features 3 Trigger cards:
- Turn on
- Turn of
- Toggle on or off
These also work as expected.
Long-term experience
At this point, I cannot yet provide real long-term experience with the devices. I have only been using them for a few days. During this short test period, the devices worked flawlessly and stayed connected to Homey. The reaction time was almost instant in my setup, although this may of course vary depending on the Matter network, the Wi-Fi infrastructure, and the overall Homey setup.
The devices also offer settings for how they should behave after a power failure. Unfortunately, this setting applies to the whole device and not individually to each button or gang. In my opinion, per-button settings would be more flexible, especially for the 2-button and 4-button models.
I tested the power failure behavior several times, and the device states were restored as configured. The devices also became available again in Homey after only a few seconds.
Final verdict
I am honestly torn between two opinions: the emotional one and the rational one.
Emotionally, I really like these devices. They are nice, different, modern, and they bring something fresh to the smart home market. The display idea is great, the devices feel good, and the concept is exactly the kind of product I would like to see more often. My heart would love to use several of them in my home.
Rationally, however, I have to admit that they do not really fit my installation environment. They do not fit into my standard wall boxes, the intended fixing holes cannot be used with the boxes commonly installed in my region, and the electrical load rating gives me concerns.
The main issue for me is that the relay rating is significantly lower than the rating of a typical lighting circuit protected by a 10 A breaker. This means the circuit breaker cannot be considered sufficient protection for the relay contacts. If the connected load is too high, the relay could potentially be overloaded before the circuit breaker reacts. In real installations, it is not always easy to be completely sure about the actual load, especially with inrush currents or future changes to the connected lamps.
So, all in all, I see these devices as very promising products with a great concept, but not yet fully adapted to the type of electrical installations commonly used in my market. To me, they still feel a bit like products with excellent potential, but also with some important hardware and installation details that need further development.
Wishlist
Dear Zemismart Team,
Here is my personal wishlist for future versions:
- Build an electronic block that fits into standard European round wall boxes and supports the common 60 mm fixing distance.
- Use a crossed or more flexible fixing system, so the device can be mounted in different wall box orientations.
- Use terminals that are suitable for different conductor types, including solid and flexible wires, similar to the solutions used by manufacturers such as Shelly or Freedompro.
- Use relays with a higher load rating, or integrate appropriate internal protection for the relay contacts.
- Make the CE marking clearly visible and provide easy access to the EU Declaration of Conformity.
- Improve the app translations.
- Add correct and complete installation and pairing instructions to the box.
- Allow the user to define the power failure behavior per gang or per button, not only for the whole device.
- Add a “detach from relay” setting, so the buttons can be used only for automations without physically switching the relay. In this mode, support for double press and long press would also be very useful.
To end on a positive note: if Zemismart built the same kind of device without relays, simply as a smart remote with display labels — either mains-powered and flat, or battery-powered — I think it could become a bestseller. For this kind of remote device, however, it would be important that the state is retained and visible in Homey. In other words, it should behave more like a switch device with a state, not only like a simple stateless button. Or even better, configurable as multi-press button or switch.
