Wait, wait, wait!
The GoControl relay is a zwave device. Zwave repeats only for Zwave, Zigbee repeats only for Zigbee.
http://www.nortekcontrol.com/pdf/manuals/FS20Z1_manual.pdf
Why are you asking about Zigbee repeaters? They can’t help with a Zwave device.
As far as Zigbee repeaters, if you do need one, see the following topic. But again, they can’t help with a Zwave device.
The SmartThings hub is a white plastic box that contains five different devices. There is an ethernet connection which is used to connect to your router.
There is a Bluetooth radio which isn’t turned on yet.
There is a zigbee coordinator which talks to your Zigbee devices.
There is a Z wave controller which talks to your zwave devices.
And there is a little tiny processor which figures everything out.
So in your house you actually have two totally separate mesh networks, one for Zigbee and one for Zwave. Devices on one don’t repeat for the other.