AndyD

Yes the HC-800 is in the rack

Yes it is connected to the 4 zone amp (audio out port 1 into audio input 4 in the amp) as well as audio out port 2 into the denon receiver 

Music services : pandora, spotify, siriusxm 

I recently purchased a home with a C4 system but the previous owner passed away and I don't know who the original installer was, so I'm a little in the dark on many items on the system.  Currently the most annoying one is the lack of whole home audio.  There are 5 zones, a 5.1 surround system in the living room (serviced by a denon receiver) and then 4zone distributed audio locations throughout the house.  I can airplay music to the denon amp for the 5.1 surround system but cannot get the c4 system working to distribute the streaming audio beyond that.  I have re-registered the system in my name so I can login to the app (the old version, OS2) and see the system, but I can't control anything.  For example, I select "audio" and then "pandora" and then get this error : service missing : "this music service is not set up in sonos yet. Please configure it in a sonos controller first".  The prior home owner didn't leave any sonos product in the homerun rack.  So I'm wondering if (1) this problem can be simply troubleshot via software/configuration or (2) if hardware, like a sonos port, is required to add on so that it can link into the denon amp (for the 5.1 surrond) and the 4zone matrix amp.  Below is my hardware.  I live in orange county California so if you have any local recs that is appreciated as well.  If this helps at all, I have installed a Unify home network system, so there is a 24port switch and UDM pro in the rack to utilize.

Denon AVR1912

Control4® HC-800 Controller C4-HC800-BL-1

Control4® 4-Zone Matrix Amplifier C4-8AMP1-B