Wireless Flood Sensors: Are They All The Same?
September 10, 2021Whole home water monitors like I reviewed in this video are great for detecting small and large leaks in your plumbing and they help you monitor and control your usage habits. Unfortunately, most of the people I know who have had significant water damage in their homes actually wouldn’t have been helped by a smart water monitor since they only monitor water on the supply side. That means that they can’t help you with leaking drain pipes, air conditioning condensation, or rain damage through your roof, foundation, or basement. For that, you’ll want something like these small wireless flood sensors. I’ve got all the most popular brands and bestsellers here to test out and I’m going to go over all things that make them different so you can choose the one that will work best for your situation.
Before we get started you should know that these all work by the same basic principle that water conducts electricity. These sensors have small conductive pads separated by an air gap, when that gap is bridged by water it completes a circuit and triggers the flood sensor to turn on and alert you of a potential problem. Fun fact from a former chemistry teacher, pure water actually doesn’t conduct electricity, so if you had a distilled water leak, these monitors wouldn’t help. Thankfully, basically all water has stuff dissolved in it and is therefore conductive, but in rare cases if you have extremely soft water, meaning very few dissolved minerals these monitors may not work as well for you.
The thing that is most likely to limit your options for these sensor is the protocol they use. The Shelly Flood and Phyn Smart Water Sensor are both WiFi sensors so basically anyone will be able to use them without the need for a hub since most houses already have decent WiFi. The Aqara, Yolink, Govee, and Orbit Bhyve sensors are all hub based, so you’ll need their corresponding hubs to connect the sensors to the internet so they can alert you on your phone. The YoLink system is using a proprietary form of the LoRa protocol which is long range and low energy, and the Orbit Bhyve is using a proprietary protocol in the 900 megahertz range, but in both cases you absolutely need to use their hub to receive the signal from your flood sensor. The Aqara sensor uses zigbee, so if you’d rather use your own zigbee hub like Samsung smartthings, hubitat, or a zigbee enabled home assistant you can easily do that. The Govee sensor is using a standard RF433 protocol, so if you already have a way of receiving those signals like a Sonoff RF bridge you could use that instead of the Govee hub. The sensors from Zooz and Fibaro are zwave, so you’ll need a corresponding zwave hub like Samsung smarthings, hubitat or a zwave enabled home assistant. If you don’t have any idea what any of those things are that I just said, disregard them and don’t pick a zwave sensor because you won’t be able to use it without buying more stuff.
Next lets talk size. As I said, these sensors more or less use the same technology for detecting leaks, so size is mostly related to the type of batteries they use. The largest sensor is the Phyn with 2 double A batteries, then the govee and yolink that use 2 triple A batteries, and very similar in size are the shelly and fibaro that each use a single CR123A lithium battery. Then you’ve got the small form factor sensors from Aqara, orbit bhyve, and zooz that all use CR2032 lithium coin cell batteries.
Having a larger battery isn’t necessarily going to increase the battery life of the product since the different communication protocols also consume significantly different amounts of power. I’m going to report the manufacturer stated battery life for each sensor, but I do find some of these claims to be pretty dubious.
For instance WiFi sensors are going to be the most power hungry, and therefore you should expect the Shelly Flood and Phyn Smart Water Sensor to have the shortest battery life. The Phyn specifically says you’ll need to change the settings in order to achieve a maximum of 2 years of battery from the two AA batteries, while the shelly flood claims up to 18 months of battery life with it’s CR123A, but again, you’ll need to change settings to make sure it wakes up as infrequently as possible to achieve those numbers. In contrast the Fibaro’s CR123A will get 2 years of battery life with the default settings using the Zwave protocol.
Surprisingly the Govee sensors say you should only expect 1 year of battery life, despite the fact that it uses the typically efficient RF433 protocol, and has two triple A batteries. The Yolink sensor can acheive over 5 years of battery life using the same two triple A batteries by using the LoRa protocol instead.
For the small form factor sensors with CR2032 batteries, the Aqara claims 2 years, the orbit bhyve says 1 year, and the Zooz sensor doesn’t mention any specific battery life, but it does say it has the new zwave 700 series chip which should lead to increased battery life over previous versions.
Another reason for the larger form factor of some of these sensors is the addition of a buzzer alarm to give an audible alert for leak detection. The govee sensor has 3 different levels of buzzer volume including a very loud 100 decibel siren that would be impossible to miss. The shelly flood, fibaro, and phyn all have moderately loud audible alerts, that could be missed if they were in a closet, basement or cabinet, and the orbit bhyve does make a faint beep when it detects water, but not enough to be considered an alert. The YoLink, zooz and aqara sensors don’t have any on device siren, so you’ll need to rely on a hub or base station to alert you.
Speaking of alerts, all of the hub based sensors can send you notifications on your phone through their various apps. In addition to that the phyn sends a text message and the YoLink, Bhyve and Govee send email alerts. For the Fibaro and Zooz Zwave sensors and the Aqara Zigbee sensor you’ll need to set up any extra notifications yourself through automations on your specific hub.
Which brings me to the subject of hubs and integrations. If you already use a home automation hub like Smartthings, hubitat or home assistant, I can tell you that the Fibaro, Aqara, Shelly, and Zooz sensors will easily integrate with your system while the phyn, yolink, and govee rely on IFTTT which is unfortunate and misguided and I definitely wouldn’t rely on IFTTT as the primary method to be alerted for something as important as a flood sensor. As I mentioned before, you can grab the messages from the Govee sensors if you have an RF bridge already, and there are some projects to modify the govee bridge to get it into home assistant, but no native integration unfortunately. I couldn’t figure out any way to add the Bhyve sensors to any home automation hub, and although they can interface with a bhyve irrigation system, that’s about it.
The next big difference in these sensors is where you can use them and how they can detect a leak. This part is particularly important when you are considering what type of leak you will be watching for. There are two main types of bottom sensor: Direct contact and indirect contact. The feet on the zooz, shelly, and fibaro sensors sit directly on the surface that you place them. This means if you are monitoring a porous surface like wood that even an indirect leak will trigger these sensors once the wood is saturated while the Yolink, Phyn, Orbit Bhyve, and Govee sensors all need to have a small pool of water before they will activate since their sensors are raised slightly and they instead sit on plastic feet. The upside to this is that they can be placed on a metal or otherwise conductive surface without triggering a false alert.
If you know exactly where a drip might come from you could also use the top mounted sensors on the Yolink or Govee, or if you want to cast a wider net, the Phyn has a special cable that will detect water anywhere along its length, but again, it needs to be relatively saturated before it will activate the sensor, so a slow drip onto an porous surface will not be detected.
The last thing to do is a little testing to figure out the minimum amount of water that will be detected by each of these sensors. To do this, I put the sensor in a bowl and slowly added water until the sensor was activated. Between each testing I emptied the bowl and wiped it dry with a paper towel. I completed each test twice, and surprisingly there was almost no difference between the first and second rounds of testing. The Phyn sensor needed the most water at 6.1mL, then it was the Fibaro, Aqara, and Orbit, all at 5.1mL, the Govee needed 3.9mL, the shelly 2.8 mils, and last the Zooz and Yolink needed 1.3 and 1.2ml respectively. I wouldn’t focus too much on the actual volume needed for each of these sensors to trigger, since this was an ideal setup with a completely non porous surface sloped towards the sensors. If this were in a cabinet, you’d likely need significantly more water before the sensors triggered since some water would soak into the wood and some would pool away from the sensor.
The other test that I performed was a range test. I put all the hubs in the same room and limited the WiFi sensors to only the access point located in that room. My first test location was in the house, downstairs approximately 50ft from the hubs and all the sensors worked fine. The next testing site was in my driveway, about 75ft away and multiple concrete walls, and at this site the aqara, and bhyve failed to report a flood alert. The next site was around 110ft where the govee, fibaro, and zooz sensors stopped reporting, then at site 3 around 150ft the phyn and shelly failed to report. The Yolink sensor, which as I mentioned uses the low power, long range LoRa protocol reported instantly at test site 3, so I continued to walk with it, testing every 100 or so, and ended up getting about a quarter of a mile away before I stopped, and at that point the sensor was still reliably reporting, and the app showed 3 bars out of 4 for signal. Just like the minimum water test, you should use these results as a rule of thumb because different signals will react differently to the building materials of your house. Also, if you have a strong WiFi network the phyn and shelly will benefit from that. And if you have a lot of other zigbee or zwave devices then they can form a mesh to get you extra range for the aqara, fibaro, and zooz sensors.
The last thing to consider are any extra features that these sensors offer. The fibaro sensor is definitely a swiss army knife sensor. In addition to reporting water and it’s battery percentage also has an accelerometer to alert you if someone or something moves it, it can be powered by an external 12V source, it has outputs for switching devices when the flood sensor is tripped, or if the accelerometer is triggered, and it has a built in temperature sensor that you can configure to have an audible alert either above or below a specific temperature.
The Phyn has battery percentage, temperature, and humidity in addition to its flood sensor, but remember that 2 year battery life? Well, to get it you’ll need to turn off the temperature and humidity reporting completely. If you have it report just once a day the battery life drops to between 1 and 2 years, and reporting 3 times a day will yield less than a year of battery life. The same applies to the shelly flood which can report temperature, but will result in significantly lowered battery life.
The Yolink reports temperature, signal strength, and battery life without significant drop in battery life by using the LoRa protocol. While the zooz and govee sensors only report floods and battery life. The bhyve sensor only reports floods and doesn’t show the battery life anywhere in the app, but I have read that you will get an alert when the batteries need to be replaced.
So here’s the full breakdown. For me, the added piece of mind of an audible alarm is worth an increase in size for placement in basements and cabinets, but I can see smaller devices like the zooz and bhyve being useful for under appliances like refrigerators and dishwashers. I really want to love the yolink sensors because the LoRa protocol is awesome, but I really wish they had a hub with a local API, if they did Yolink might get all of my sensor business. Yolink does have a published API and says they are working on a cloud based integration with home assistant, but as of now it’s not available so you’re stuck with IFTTT or Amazon Echo integration.
Overall, all these sensors are so cheap and so easy to setup that there’s no reason not to have them in trouble areas like your water heater, dishwasher, and laundry room where leaks are most likely to happen. I’ve got links to each of these sensors in the description, let me know in the comments which one you decided on and why.
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