The Sonoff TRV Gen2 is a Zigbee thermostatic radiator valve.Straight up front, I can’t show you it running fully right now because I don’t have any radiators, but towards Christmas I shall install this on my livingroom radiator back in the UK.For now, I can tell you that it worked out of the box, no problems, and is a nice little unit.
To start the ball rolling, rather than delve into the Sonoff eWeLink app, I simply paired the TRV with my Home Assistant Zigbee2MQTT instance.I turned the dial to OFF and held in the centre button for 2 seconds+ – a new device appeared in my Zigbe2MQTT device panel after I hit ALLOW JOIN and waited a few seconds.I renamed the device to TRVGEN2 and made sure that I ticked the UPDATE HOME ASSISTANT option box.
Immediately nothing happened so I left the unit alone for a few minutes and came back.Voila.Although it will be a while before I can test the various settings: heat percentage, hourly, idle steps, frost protection temperature and many more – all shown below.
All of those I’ll be able to try when I get to the UK, and I’ll update the blog then.Up to now, it’s all looking promising.You can set up schedules for the entire week if you want to.
And of course, via Home Assistant, assuming you have some means of using Home Assistant remotely on your phone (I use Tailscale), you can obviously override anything on your phone.Ignore the unknown temperature sensor.I’ve since changed that to internal.
The display is lovely, full color, and you can turn it at 90° to any angle.I guess normally you would normally have the unit at the top of the radiator, but not everybody will do that.Simply turning that dial at the top along the edge, you can change the set temperature from 5° All the way up to 30°.
Pressing the centre button once toggles the TRV between manual mode and timed mode, also double-click lets you turn the display upside down and sideways.It’s nice to know they give you the option to use an external temperature sensor, because having a temperature sensor inside a radiator valve is handy, no doubt, but ultimately useless (because really, you want to know the temperature of the room at the opposite end of the room to the radiator).I have seen many devices that don’t take this into account.
I’m pleased to see that, rather than use a tiny little battery, which will need changing every five minutes, this one uses a pair of AA batteries.It came complete with batteries, so I didn’t have to install anything.Until I get this fitted on a radiator, that’s about it for now.
Quite impressed initially.Entities like an open window detector I certainly won’t be able to test for a while until it’s actually cold outside and I’ve got it sitting on a radiator, but I’ll just assume that works.It’s quite an impressive array of sensors and calibration controls in Home Assistant right at the outset.
Remember, as I’m writing this, the device hasn’t even been released yet.Finally the TRV Gen2 came with a rangeof adaptors for different type of radiator attachment.Here’s a photo showing the base with no adaptors fitted.
Here are the entities that appear in home Assistant.
Read More
