Trouble Shooting
It seems that most of the situations where you can face "No response" in Home app are due to networking issues.
Some routers and access points allow the usage of a single SSID name for both 2.4Ghz and 5Ghz. This can create some issues and it's recommended that you keep separate networks for 2.4Ghz and 5Ghz with different SSIDs.
If you want to read more about this, please look into issue #215
If you have an unmanaged switch this might be the problem, since they probably are not handling multicast / MDNS very well. You can try to replace your switch with a managed one where you can tweak these settings.
If you want to read more about this, please look into issue #215
The default for most routers and access points is to have the WiFi channel set to automatic. This might be not your best option. You should use some wifi scanner app to figure out which channel is more available around you to avoid unnecessary interference and consequentially drop in connectivity.
Note 1: If you have more than one access point, you can set them both with the same SSID, but be sure to have different non overlapping channels configured there. Note 2: On 2,4Ghz networks, the best non overlapping channels are 1, 6 and 11.
If you want to read more about this, please look into issue #215