Over time, I tested several TRVs for my radiators, and it’s time I add another one from the brand I always wanted to try. I heard good things about Meross, so when they emailed me to try their products I said: Yes! Here we are with the MTS150 TRV from Meross (AmazonUK|AmazonUS) and I have some words about this TRV.
Smart TRV by Meross
Inside the box, I found a new TRV coupled with a small hub. These can be purchased as a set, but you can also get just the TRVs if you already have a hub from Meross. The hub is needed, as Meross uses RF 433MHz to speak to its products. While the protocol may seem dated, it provides excellent range and low power consumption. ZigBee is my go-to protocol nowadays (Sonoff TRV, Moes TRV) but let’s see how well Meross TRV works first.
The Meross hub (MSH300) isn’t particularly exciting. It comes with a pairing button and a micro USB plug for power. What happened to USB-C? In line with most smart things, it uses 2.4GHz WiFI to speak to the Internet. Each hub can link to 16 devices at once.
If I had to name the strong points of the hub, it would be the fact that it supports SmartThings, HomeKit, Google Home and Alexa ecosystems, and it’s very easy to hide due to its small size.
The Meross TRV (AmazonUK|AmazonUS) is white and featureless. The top of the device is covered by a capacitive touch LED display that turns on upon touch. The display offers basic information about the current setpoint, internal temperature, heating mode and connection. It also allows for basic adjustments thanks to 3 button controls (or 3 control surfaces). The display is bright enough to be used during the daylight.
Meross TRV requires 2 x AA batteries (rechargeable batteries are not recommended due to lower operating voltage – that’s a shame) and it comes with 6 adapters to accommodate the most popular valve types.
How much?
As the thermostat makes good impressions, I was curious, how much I’d have to pay. Expect to spend around $60 for the set with the hub and an extra $38 for each Meross TRV purchased on its own. They are not the cheapest TRVs I used – the cheapest ones were from Moes, but they rank somewhere in the middle between the budget-friendly Moes and premium ones from Aqara.
Installation
I’m lucky, as my test valve needed no adapters. Meross TRV simply screws into my thermostatic valve and just works. Refer to the manual and product page to confirm your valve type. In essence, remove your non-smart thermostatic head, screw in Meross TRV and you are ready to go.
If you want to upgrade your system, but your radiators don’t have thermostatic valves (ones that are activated by pressing down on the valve pin), you’ll need to modernise the valves as well as add a smart thermostat. It will cost you much more in labour and parts.
Meross ecosystem is different
I run myself into a dead end, frantically trying to pair the Meross hub with the app without luck. It turns out, that Meross has a slightly different approach. The process of adding the smart device – in this case, Meross TRV includes the hub pairing. Instead of looking for the hub to add first, select the device type from the menu, then follow the instructions to add both – your Meross hub and TRVs. It was the missing piece of information I needed!
From there, I quickly zipped through the mechanical calibration, hub updates and setting up the Meross TRV. During the initial registration, the app informed me, that the Meross TRV can take up to 3 min to register the changes. This is done to reduce the battery life. In practice, your wait could be shorter depending on the temperature changes.
Meross app
The Meross TRV controls are neatly laid out in the app, with the most important ones available on the main screen. I had to customise some of the preset values, as I won’t be using 27℃ as my HEAT option! The default values were not appropriate.
A quick trip to settings allowed me to set the correct defaults but also access other important features like internal sensor calibration, and mechanical calibration (which can be also done on a schedule).
Great scheduling
I really liked how Meross resolved scheduling. The entire week is laid out as a day temperature chart which I could adjust simply by sliding the values to the correct positions. The whole system was incredibly easy to set up and it made me want to have something like that in my DIY Smart Heating 3.0 I made in NodeRED.
There are some limitations. Each day is split into six time periods. You can’t add or remove them. While you can select the same schedule for multiple days, there are no options to copy our settings to be used on another TRV. In reality, it’s enough and the hard limit comes from the fact that these schedules are stored on the unit, just in case the hub/could goes offline.
To top up the list of smart features, Meross TRV also comes with open window detection and notification about the low battery.
In use
I found Meross TRV to be very quiet when connected to my test valve, but bear in mind it’s a brand new valve. If your TRV is loud, perhaps you should investigate the valve it is attached to. How hard it has to work, will also be detrimental to how long the battery will last. I had the unit connected to the test valve and exposed to my typical temperature changes – and it lasted about 5 months before issuing a low battery warning.
The only thing that I found slightly annoying was the display. As the display had no marks on it, I found myself not sure where to press it to wake it up. I simple dot printed on the otherwise blank display would fix it (the O button is next to the grill for the temperature sensor). I know in reality, I’m more likely to use Alexa controls and the app to make changes, but I can’t help to note that imperfection.
My testing for the range has been reduced significantly, as I no longer live in a 4-bedroom house, but in a spacious 2-bed apartment, I have not found a single dead spot. It’s RF 433MHz – it comes with pretty decent penetration.
Smart Speaker
I tested Alexa & Google Home integration, both integrations are seamless, problem-free and working without delay. Both assistants report the setpoint as well as the internal temperature associated with the TRV. Changes made from the app, through the voice controls and via thermostat were reported on the Meros TRV in less than 3 min.
I don’t have SmartThings or HomeKit but if my current integrations work this well, I don’t expect these two to pose any problems either.
Hacking?
I haven’t tried to hack this. Because the device is using RF433 comms, it could be possible but it’s beyond something I want to do. For that, I have a nice Sonoff TRV to play over ZigBee. One thing to remember, is that you can use the AlexaRemote node in NodeRed to obtain information about Alexa-enabled devices or use the GoogleNora node to do it via the Google Home ecosystem. These two would enable interactions between DIY automation and Meross TRV.
Final thoughts
Meross TRV (AmazonUK|AmazonUS) is an interesting choice if you are not planning on hacking the heating system any time soon. It works well, the battery is sufficient to last through the winter season and the quality of the product feels adequate to its pricing. Meross won’t win the hearts of the DIY crowd, but it’s a cheaper alternative to premium TRVs from Aqara. Would you agree? Let me know in this Reddit thread.
🆓📈💵 – See the transparency note for details.
