@David-TP 

I read on the Support FQA "When the Deco system works in Access Point mode, there must be the main Router in front of the main Deco, providing Internet. In this case, the main Deco and other Deco units are basically equal, they are clients of the main Router."

After reading other posts, I see AP does not lead to the Deco unit taking on the SSID of the main router. It does not make sense to me that they have their own SSID. I guess I should have just gotten a wireless extender as I have my Comcast router/gateway in my first floor office with ethernet connection to Deco main unit on second floor  which is wifi connected to ancillary units by front door and in garage. A wireless printer on the first floor in another room from my office will not print from my office computer, presumably because it is linked to a different network (the Deco network) from my computer (Comcast router). I tried changing to Access Point mode and it did not change anything. But the Deco signal is not strong enough in my office for my office devices to connect. So I am stuck with 2 networks if I want full-house coverage.

Are there any other suggestions besides trashing this whole thing and just getting a couple of wireless extenders? The information describing how this functions was misleading. The official description of Access Point mode made it sound like the Deco took on the SSID of the main router.