I have moved into a house with Connect:Amp installed (I think it is likely more than five years old)

I have installed the Sonos 1 app and it can find the unit after I turn it on with a factory reset (power on whilst holding the top button (mute button). 

The app then asks me to press and release the top two buttons (mute and volume up) but then never proceeds beyond that. The unit light starts flashing orange.

The Connected:Amp is connected to my router via an ethernet cable and is connected to the same network as my iPhone