How to bind/pair a Sunvic wireless radio heating controller to its receiver
1/ Grab that handy paperclip you keep for poking and hooking things.

2/ Hold the On Off button on the receiver for 3 seconds or until the green LED flashes.

3/ On the back of the controller, with your paperclip, press/poke the Learn button.

Note that the Red LED means 'working' while the Green LED means 'you're going to freeze in your own house'. This might be something to do with Chinese manufacturing and red being their most positive colour.