Shelly BLU TRV in the test: energy saver for smart home tinkerers

Shelly is particularly popular among smart home enthusiasts for its inexpensive and versatile flush-mounted actuators. With the BLU TRV it’s coming now second generation of a smart radiator thermostat onto the market – with numerous improvements.

The most striking innovation is hidden inside: Instead of WiFi, Shelly now relies on Bluetooth. This protects the batteries. According to Shelly, they should now last up to 2 years. However, a gateway is required for the connection to the router. It is supplied in the form of a small USB stick and can be plugged into an existing mobile phone power supply.

If you later want to upgrade your heating control with additional thermostats, you will receive additional USB sticks – which may also be necessary. Through the limited range of Bluetooth The connection to the radiator thermostat may be broken in the next room.

Shelly BLU TRV in the test: Discreet design

A lot has also changed visually: the completely white radiator thermostat in the shape of a cylinder is hardly noticeable on the radiator. By turning the thermostat regulate the temperature in fine 0.1 degree increments. The white LEDs on the head initially show the current room temperature and then switch to the set target temperature.

Disadvantage of the display on the thermostat head: In many cases you have to bend down to read it. In the worst case, your head is against a wall and the temperature display remains hidden. Other manufacturers solve this more cleverly and position the display on the long side, which allows the display to be aligned upwards or forwards.

Shelly BLU TRV in the test: Versatile control options

When you turn the control, the pleasantly quiet motor starts. Alternatively, the temperature can be set via the Shelly Smart Control-App determine. The app allows many different settingsfor example enabling “Accelerated Warming” and “Automatic Calibration”. A special feature: The Shelly BLU TRV can even control the underfloor heating by mounting the controller on the underfloor heating valve.

However, some functions that would make heating control easier are also missing. For example, only one temperature change can be set per schedule. So you need four schedules for a typical daily routine with night-time reductions, morning warming, lower temperatures during the day and higher temperatures again in the evenings.

With many other radiator thermostats, a schedule is sufficient. A central “leave house” function, which lowers the heating temperature in the entire apartment, is also difficult to set up.