Controlling radiator with bluetooth on RPi3

Source: http://torsten-traenkner.de/wissen/smarthome/heizung.php

sudo apt-get install pi-bluetooth // not needed, check it
sudo apt-get install bluez bluetooth

sudo -i
hciconfig hci0 up
gatttool -I -b XX:XX:XX:XX:XX:XX
connect
char-write-req 0x0047 00000000
char-read-hnd 0x003f
disconnect
exit

Another solution
Source: https://github.com/im-0/cometblue

Checked on Ubuntu 16.04

Prerequesites:

sudo apt-get install pkg-config libboost-python-dev libboost-thread-dev libglib2.0-dev python-dev libbluetooth-dev

Then install cometblue

sudo apt-get install libglib2.0-dev
apt install python-pip
pip install cometblue