I'm with @GreenMan .  Disable the WiFi on the Z3 and get something like an MR36.   The first thing you'll notice is the better coverage the MR36 provides.  You can position the MR36 closer to the middle of where you need coverage (you still need to get a cable to it). If you need, you can then getting a second MR36 for MESH.  Note that your throughput drops by more than 50% when using WiFi through that MESH MR.     Going sideways; I've had a good experience using the DLink power link extenders (which extend your network over the power lines in your house) ... ... View more