Refoss Smart Home Energy Monitor, Native Open API & Web UI (No Cloud Required), Real Time Electricity Usage Monitor, Power Consumption Meter Works with Home Assistant & MQTT, Solar Net Metering, ETL

I’ve been using the Refoss Smart Energy Monitor for a week now, and I’m thoroughly impressed. One of the standout features is its local integration with Home Assistant, which is precisely why I chose this energy monitor. The instructions were straightforward, and the video on the Amazon listing was particularly helpful, guiding me through the entire installation process. It should be relatively easy for anyone with basic electrical knowledge and some handy skills. However, I recommend doing some pre-planning before installation to determine which circuits you want to monitor. There are five L1 circuit sensor, five L2 circuits sensor, and six circuits sensor that can be used on either L1 or L2. You’ll need to choose one or the other. Additionally, you can combine some circuits and use one clamp for them, as long as they don’t exceed the current limit of the circuit sensor. For instance, I combined two kitchen outlets into one, saving me a sensor I used for monitoring a different. For balanced 240V loads like an AC unit or an EV charger, you can use one clamp and then change the circuit factor to 2 in the Refoss app or create a helper in Home Assistant that multiplies the energy usage by 2. This is because with balanced loads, the energy drawn on both lines is the same, which is why it’s called a balanced load. This way, you can save a sensor to monitor another circuit. I highly recommend making a note of which sensors are connected to which circuits to avoid wasting time trying to remember where you connected them. Setting up the energy monitor on the app was a breeze. I simply downloaded the Refoss app, followed its instructions to connect it to Wi-Fi, and updated the software of the energy monitoring module. The Refoss app allows you to monitor live energy usage for each connected circuit and view a history of energy usage for each circuit, broken down by day, week, month, and year which is awesome for using the app on its own. Connecting to Home Assistant was equally easy. I searched for the Refoss add-on, and the energy monitor was automatically detected on my network. It brought over all the entities shown in the Refoss app and then I got to setting up everything in home assistant. Overall, I highly recommend this affordable and reliable whole-house energy monitoring system. If you use Home Assistant, this is one of the best options out there that is supported natively through the Refoss addon.

When I received this product, I was initially impressed by how solid it felt in my hand. It is heavy and feels extremely well-made. The provided instruction manual was intuitive and written in perfect English (based on experience, this is a HUGE plus). After cutting the main breaker that feeds my electrical panel, I was able to remove the panel cover and install the device in under an hour. I initially had a little trouble routing the wi-fi antenna, but finally decided to let it hang from the bottom of my box. In an installation with a surface-mounted panel, this would be much easier. My only issue with the installation was cosmetic. The wires running from the clamps to the device's brain use molded plugs and cannot be adjusted for length. It would be a neater installation if these cable lengths could be customized, but I consider this nitpicking, and it did not change my initial rating of the product. Since I had already installed the Refoss garage door controller at the house, I already had the application on my iPhone. Adding the power monitor was as easy as hitting the "+" in the app to add it to the dashboard. After a little configuration of my circuits, so that 240-volt breakers appeared as a single device, the installation was complete. The app was now showing me the power consumption of my monitored circuits in real-time. While the device works exactly as designed, and the installation went flawlessly, the app could provide me with clearer information. The real miss in the application is the inability to rename (or even add footnotes) to the circuits. If they could add this ability, it would make a huge difference. You should also be able to arrange the circuits in a custom order so that my mains could appear at the top of the app rather than being listed in alphabetical order. All in all, this is a great little device that will provide me with excellent insight into my power consumption at home, enabling me to make informed decisions about sizing a solar system in the future. It will also show me where I can reduce power usage when I need to look at installing an emergency generator.

Have this product managing power usage in out house along with the Homeassistant management software. It took about 2 hours to plan out and install. While I was comfortable doing the work myself as an electrical engineer. I wouldn't recommend it for most DIY folks unless they are able to completely disconnect their main outside the house before the breaker box. Wifi connection worked great. VLAN automatically setup with no issues. Size was good for my breaker box, not sure if it would be as easy for an older or smaller box. Two issues I had, the install is a total mess of wires... it wasn't that easy to clean up. Wish there was a way to integrate current monitors into the breakers themselves. Second issue is the current readings were ALL backwards, despite following the directions to a T. Fortunately you can toggle this by adjusting your multiple from positive to negative in the app. Unfortunately thats annoying to do because of some android bugs making it hard to type "-" in their app? Look is ok if you don't mind the rats nest of orange wires in your breakerbox. Cost seems appropriate given the components included. Just wish they included another 5-10 breakouts to cover a full box, or at least the capacity to add them from an expansion kit. Kit should be durable and last for years with no major moving parts. Curious to see how well the plastic clips hold out over the years if I have to move it ever...

Great device! I upgraded from an older unit that only had 2 leads for the mains. I was able to installed in about 30-45 minutes. It was pretty straightforward, the directions were clear. It seems like it’s very well made. It was a little challenging to find a place in the electrical box, but I did find a place for it in there eventually. It looks much nicer than my older unit as this one is contained in the electrical box and is powered by tapping into a breaker. Super clean look and you can’t tell it’s there aside from the antenna. The app works well and it was easy to get connected to WiFi and HomeAssistant! I’ve had issues with a few device due to mesh network and had to tinker with configs and settings in my router. Now I can set alerts, monitor, and automation tasks a little more granular. This thing is solid! My only complaint is that I didn’t have enough leads to monitor each breaker. If you have anything running on 220 it likes 2 leads (but you can use 1 and change a setting to “calculate”, it’s just not as accurate using a single lead). I was still short a few leads using the single leads on the 220 breakers. You call still get the overall usage that you are consuming from the one that connect to the mains., so it’s not really that big of a deal.

I’ve been using the Refoss Smart Home Energy Monitor (EM16) for a few weeks now, and I’m seriously impressed with what it offers. As someone with a solar setup at home, I was particularly drawn to the Zero Feed-In Automation feature—and it works beautifully. Now, instead of sending excess power back to the grid for pennies, the system smartly kicks on high-energy appliances like my water heater and EV charger when solar output peaks. It’s already making a noticeable dent in my utility bills. Installation was straightforward with its clamp-on design, though I'd recommend a bit of caution when handling the current transformers as instructed. Once installed, everything syncs quickly with the Refoss app, which is clean and user-friendly. You get real-time data for each connected circuit—power, voltage, current, and power factor—plus clear breakdowns by minute, hour, day, and even year. The recent update (July 2025) added some killer features: ✔ Merge channels ✔ Export hourly-level data ✔ New energy stats page ✔ Invert CT readings without physically flipping the wires (huge time-saver)Another highlight is the smart alerts. I set thresholds for various appliances, and when something goes over the limit—like my dryer running longer than expected—I get an instant push notification. Great for both safety and savings. Also, it integrates with Home Assistant, which lets me automate energy usage smarter than ever. I love that all data stays local—no cloud dependency, which is a big privacy win. Only downside? It doesn't support Delta 3-phase, but for typical residential setups, this thing is perfect. Bottom line: Whether you're just energy-conscious or running a full solar + smart home setup, the Refoss EM16 is absolutely worth it. I’ve already seen more control over my energy usage and expect long-term savings. Highly recommend!

I couldn’t be happier with the Refoss EM-16! I love having a smart home and I enjoy adding tech that makes our lives easier, is simple to use, and just makes sense. I shopped around for an energy monitoring system for a while and decided the Refoss EM16 was the way to go. This was the right choice! The installation was far simpler than I expected. The included headphone-jack style connectors made wiring a breeze — no tiny screws or fiddly clamps to deal with. I had read reviews that talked about the extra wire since these can’t be trimmed, but as you can see in the before and after photos of the breaker panel, the slack is easily manageable. Refoss labels all the clamps to make attaching clamps and connecting to the unit a breeze. I took my time to be cautious, and I was still able to hook everything up and have it running in two hours, without any special tools. The EM16’s connection to my WiFi is strong and it hasn’t dropped at all. Refoss gives you all you need to connect your power wires including the wire nuts and extra wire. I was extremely happy and slightly surprised to see how well the instructions are written and easy to follow; no missing words or “lost in translation” instances at all. To make your install fast and easy, plan out in advance what circuits you want to monitor. You can also use a single clamp across two wires (in the case of dual breaker circuits like A/C or hot water heater), allowing you to use more clamps to monitor more circuits. The app itself is outstanding. It guided me step-by-step through setup and immediately started giving me clear, real-time data. The interface is clean and intuitive, making it easy to see my usage at a glance and drill into details when I want to. You can set alerts and automations easily through the app. You can also plug in your price per kWh for power and the app will tell you what your current cost are (see pics). This even helped me to find I had two circuit breakers mislabeled and one isn’t even connected to anything! Our home is only 7 years old and that wasn’t found by two previous home inspections! Since I love home automation, integration with Home Assistant is important to me and the process with Refoss was seamless. Once connected, it showed up right away and has been rock-solid ever since. I can automate notifications, track energy trends, and even display the data on my dashboards with minimal extra effort. I even have automations to turn lights different colors when the clothes washer or dryer is done so we don’t forget to dry and fold them. Overall, the Refoss EM-16 is a fantastic product if you want reliable energy monitoring with minimal setup hassle and full smart-home integration. I only wish I had bought and installed this sooner! Highly recommended!

So far, the Refoss 16-channel power meter has been pretty solid. Install was straightforward, and the hardware feels high quality — about on par with Sense or other higher-end monitors I’ve used. My only small gripe on the hardware side is that it’d be nice if Refoss offered some CT clamp extension cables to help clean up wiring in a 200-amp panel. I have had no issue with the units integrated wireless receiver and it has been very reliable. The app itself is decent, but if you’re coming from Sense, it’s definitely a step down in polish. There’s no device detection or load learning, which feels like a weird omission these days. I’d love to see options to merge CTs in the app or have a bit of smart recognition when certain appliances (like the fridge or microwave) kick on. That said, this thing absolutely kills it with Home Assistant. That’s really where it shines. Setting up automations and triggers off individual clamp readings has been way more reliable than Sense ever was, and honestly, that alone makes it worth the upgrade. Overall, the Refoss delivers great hardware, accurate readings, and solid integration potential. The app could use some love, but if you’re the kind of person who enjoys tinkering and wants full control over your power data, this is a great pick.

I've been dying to get a handle on my electricity bill, but figuring out which appliance was the real energy hog was impossible. The Refoss Smart Energy Monitor finally fixed that. If you're tired of just guessing or getting those vague "usage summaries," this is the way to go. It monitors the whole house with 16 individual circuit clamps. I can finally see what my AC unit pulls vs, say, the lights or the garage subpanel. Getting that granular detail is perfect for finding those sneaky power drains. Now, full disclosure, you are opening your breaker panel, but the install itself is surprisingly smooth since it mainly relies on those CT clamps. And for any other Home Assistant users out there: this thing is gold. The local integration worked like a charm for me. It was pulling real-time voltage and power data right into my dashboards almost immediately. No messing with slow cloud services or waiting for hourly updates; it's fast, reliable, and exactly what the smart home community needs for serious energy tracking. If you're a power-monitoring nerd like I am, you need this. The data is accurate, the 16 channels let you track everything you could possibly care about, and the setup was genuinely frustration-free (the manual was even solid, which is a rare win!). It completely justifies the price by taking the guesswork out of energy usage. Highly recommended for the serious smart home enthusiast looking to save money. Note: my clips were backwards so I had tyo reverse them to get the proper numbers. Try setting one up first to make sure you have the direction, then finalize it.

I have been trying out the Refoss EM16 Smart Energy Monitor for a while now, and I must say, I'm impressed. It was easy to install—good instructions and helpful online videos meant the whole process was simple and quick. Took about an hour to have everything up and running, and all plugged in to the Refoss app successfully. I like best that this product is so versatile and thoughtful in design. You can just plan and label your circuits ahead of time, and if a clamp is showing up in the negative direction, you can simply reverse it in the app without the need to rewire. If you require additional circuits to be monitored, you can bus their wires together into a CT so long as they're on the same phase. The application is simple to operate, giving real-time monitoring of all the circuits, and detailed energy history by day, week, month, or year. Home Assistant support is where this product really shines. EM16 auto-commands and provides complete local access to all the data of each circuit, enabling advanced automation without the cloud. Solar system owners will love Zero Feed-In Automation—putting extra solar energy to use powering devices such as EV charging points or water heaters rather than returning it to the grid. The recent firmware releases saw the addition of various useful features, including channel merging, export of CSV data, improved dashboards, and inverting CT readings in software. The releases show that Refoss is refining the product according to feedback from users. Overall, the EM16 is a wonderful, budget-friendly energy monitoring system—easy to install, full of data, and ideal for smart home residents as well as anyone wishing to gain better control of and track their home energy usage. Highly recommended.

I was pleasantly surprised by how easy this device was to install. The documentation is clear, well-structured, and provides all the necessary details to get started quickly. If you need extra help, there are also several installation videos available online, which can guide you step by step. Personally, I was able to complete the installation in about one hour without any major issues. It really is just a matter of following the instructions. Once the hardware is in place, all you need to do is download the Refoss app on your phone, and the setup takes just a few minutes. What I really appreciate is that it’s also compatible with HomeAssistant for those into home automation. It integrates smoothly and is very easy to configure. Overall, this product is extremely simple to install compared to other, much more complex solutions I’ve used in the past. Highly recommended for anyone looking for an easy-to-use smart energy monitor.

Overall a good product after monitoring for a few hours. The app could be more user friendly and organized a bit better. Like some others have said some sensors are wired backwards and will give you a negative value even if installed correctly but is easily overcome with the circuit factor. About half of mine were wired incorrectly. I wish the pig tails were a bit longer to give more options on where to mount the receiver but overall installation was very easy. So far so good, the product is giving me lots of information about energy consumption like it was designed to do. Would recommend

I'm very happy with the EM 16. It does everything I was hoping it would. Install was easy. It took max 30 minutes once I got started. The app connected without issue. I installed all circuits as called out in the instructions but some circuits were showing negative power (as in energy flowing back to the grid) which was definitely not correct. I think that has more to do with my house but either way there are 2 ways to fix that. Either flip the clamp or set the power factor to -1 in the app which is essentially the same as physically flipping the clamp. The Home Assistant integration is great. There's almost no setup to connect it. The integration is native so when I added it to Home Assistant it connected itself to the EM16 without any additional inputs. Tips: - Install is really simple, power off to the whole house, connect the WiFi antenna, connect the power lead directly to a circuit, attached the clamps. - Do some planning before install. Consider which circuits should be monitored if you have more than 16. I wrote it out on excel first which made revisions before I started the install easy. It also made it easy to rename the circuits in the app after setup was complete - Mark the circuits you've planned on the breakers since the circuit numbers won't be visible when the panel cover is taken off. - There are 3 types of clamps, A, B, and C. A and B clamps need to be on different phases. C clamps need to adopt either the A phase or the B phase but they can't be on both. On North American panels, generally, each row of circuits (assuming the panel is oriented with the long edge vertically) is on a single phase. That means starting at the top of the panel and working down each row alternates phases. The photo with the panel cover is after the install. Apart from an antenna there’s no sign of the EM16.

I self installed this on my 200amp panel and it works very well. Installation was straightforward as long as you’re comfortable doing work inside the panel (make sure the power is off!). It’s been really useful to see where unexpected power draws are coming from, such as a heater in one of my adult children’s rooms that I did not know about! Recommended for all who enjoy having details of what’s happening in their house.