Even though I have the original Sonoff TH, I don’t believe I ever covered it on my website. A simple take on a typical Sonoff switch with a temperature twist. It is a fairly popular device, as the temperature probe can be used to control water features, heating and more. Today I received Sonoff TH Elite (and Sonoff POW Elite) and – wow, Sonoff no longer feels like a budget device in my hands!
Sonoff TH Elite
If you worry about elite pricing, don’t. Sonoff TH Elite comes in 2 flavours: 16A and 20A and it’s still reasonably priced. The beefier version will set you back $19.99 while the “lite” one costs about as much as the original one: $16.99. Just note, that probes have to be supplied independently:
- MS01- Smart Soil Moisture Sensor ($12.99)
- DS18B20 – Waterproof Temp Sensor ($15.29)
- Si7021 – Temp and Humi Sensor ($15.29)
- AM2301 Temp and Humi Sensor ($15.29)
- RL560 5M Sensor Extension Cable ($3.99)
You can match the sensor to meet your needs and take advantage of the different properties of each probe. Pay attention to the sensor type, as it will define not just the temperature range, but the max length of the extension (for up to 60m). It’s really handy if you have to monitor things away from home. These probes use RJ11 (telephone connector) to connect to Sonoff TH Elite. It will prevent the sensor from accidentally slipping out, but anyone with older sensors will face compatibility issues.
Sonoff Elite:
Get the latest devices from ITEAD – the new product line: Sonoff Elite includes:
I never had to use one, as I turned a Sonoff Basic into a Sonoff TH equivalent by adding a DHT11 sensor to it and flashing the switch with Tasmota. This turned the $5 into a smart controller for my DIY Smart Heating System. I don’t think I will replace the current setup with Sonoff TH Elite (even though I could), as I already have a ZigBee based thermostat lined up for this role.
Got the looks
There is no denying that the Elite series of the Sonoff devices have really handsome looks! DIN rail mountable by default, Sonoff TH Elite sports uniform white body with minimal prints. The surface is dominated by an LCD display that refreshes the data every 5 sec. While a display highlight would be nice, it’s unlikely you will ever take on electrical work in the dark, so I will let this one slide.
The display will show you the current temperature and humidity of the attached probe, so you don’t have to reach for your phone to troubleshoot things. I only wish that display had more information present like network details, schedule etc as in reality, it’s easier to pull out the eWeLink app and access the data than move to the physical location of your Sonoff TH Elite.
I have the drive to look at Shelly’s Pro 4PM controller, as it vaguely resembles in shape and function device from the Sonoff Elite series. I’ll get to that once I finish my look at the Sonoff POW Elite, as they are more similar to each other.
It’s clear to me, that with a single button, Sonoff TH Elite controls will happen over the eWeLink app, but the button allows you to quickly enable/disable Auto mode. A brand new addition is the inclusion of the dry contact at the top of the unit. Remember, this isn’t a heavy-duty relay (5-30V, 1A Max), and is used to switch other control circuits.
Sonoff TH Elite has a single channel really and 4 terminals. Two to connect the power, and two to control your main circuit. Depending on the model (THR316D/THR320D) it will handle 16A and 20A respectively.
New in the eWeLink app
The new interface in the eWeLink app brings features designed specifically for the Sonoff TH Elite. The switch interface has 2 modes – manual, where the sensor data is gathered and displayed in graphs, but the temperature and humidity values have no influence over the relay and the Auto mode in which the state of the relay is driven by the policies set in the app. You will be able to add up to 8 policies for temperature and humidity control where you can control the internal relay of the Sonoff TH Elite with values (higher/lower) from the probe. The schedule for these policies can be also defined so they don’t apply 24/7.
On top of that, the eWeLink app brings the LAN mode for local control, power-on state and inching. Fans of the imperial units will find the toggle for these and units will be converted in the app as well as on the LCD display.
The standard eWeLink controls are there too including schedules, timers and looping. In the automation panel, you can use the temperature, humidity and relay state as triggers and set the relay state as an action.
Sonoff TH Elite has also push alarms for temperature and humidity thresholds. You can set these and you will receive a notification on your mobile device when the threshold is reached. A handy way of keeping in touch with your automation without opening the app.
Smart controls
As eWeLink comes with skills for Alexa and Google Home, you can control your Sonoff TH Elite via voice commands and appropriate apps. Additionally, controls can be invoked via Home Assistant and NodeRED thanks to eWeLink API.
What’s nice is the inclusion of the temperature readout in Alexa and Google Home. You can ask your smart assistant about the temperature of your Sonoff TH Elite, but not the humidity.
In use
Sonoff TH Elite responds quickly in the LAN mode and via the cloud. The relay inside it is pretty loud and you will hear it toggling back and forth. At first, I had some delays toggling the lights on and off, but that settled after a couple of mins and the device got more responsive after 1-2 min. In a similar way, the sensor data was inconsistent and I had the temperature and humidity probe dropping the packets. I think one of my sensors is bust, as the other thermal probe has no issues and reports back without skipping.
I mentioned that the button on Sonoff TH Elite can change the mode of the relay from Auto to Manual (double click), change is reflected on the unit itself by a barely visible LED. An icon on the LCD would be nice to make the change of mode more visible. A single click on the button changes the relay state. What’s a little bit annoying is the fact that after enabling Auto mode, going to manual mode in the eWeLink app doesn’t override it. You have to go to Auto mode again and disable it.
By default, the LCD screen shows the temperature and humidity data. If your probe only reads one, the other value will be blanked out. These are updated every 5 sec and sent to the eWeLink cloud. Data from sensors is stored in the app but at 1h intervals. There are no aggregation settings to control that and even though the sensor delivers new results every 5 sec, there are no options to retain that information. It can only be used to trigger policies.
If you have an Auto mode on, pressing the Sonoff TH Elite button will toggle the relay state and return back to the desired state rather than preventing the user from interrupting the power. It would be nice to have control over this behaviour too, as we all have different needs and an accidental button press could ruin someone’s day.
Lastly, the dry contact relay has no interface. The relay behaviour will mirror the state of the main channel and it’s down to you to wire it correctly (*NO/NC). It would be nice to have programmatical control over that as well.
Elite on the inside?
Bluetooth pairing (and the promo materials) reveals ESP32 inside (ESP32- D0WD-V3) with a faster CPU than the original switch. It also means that the device has Bluetooth & WiFi in the 2.4GHz band. Sadly no 5GHz compatibility.
Traditionally, Sonoff devices come with everything you need to tinker with the firmware and Sonoff TH Elite is no different. The PCB contains pads to flash the ESP32 inside (TC,RX, GND, Vcc) and something tells me that the main button is wired to GPIO00 to enable the flash mode.
The relay on my model (THR320D) was rated for 20A and the dry contact one for 3A. Extra dev pads are exposed on the other side probably to access the LCD IC – so it’s a matter of time before we going to see Tasmota running on it.
I don’t have any information about support for Sonoff DIY mode. It would be nice to see for anyone looking to integrate these with DIY automation without flashing with Tasmota or using eWeLink API.
Final thoughts
I’m somewhat impressed with Sonoff TH Elite. It looks nice and brings interesting options to the table including new probes, dry contact relay and an LCD display to make monitoring as simple as possible. As Sonoff TH Elite still keeps the price low, if wanted to use an all-in-one thermostatic switch – this could be a no-brainer. Let me know what you think about the Elite series from Sonoff in this Reddit thread.
🆓📈 – See the transparency note for details.
