Hello,
If I buy any 240 volt plug in Z Wave device, will it act as a repeater?
I have a shed that I want to put a battery powered motion sensor in as a security device. If I put a powered device in between that and the hub would it extend the range?
Thanks
Most will, smoke sensors and other emergency devices may not as they don’t want to delay a smoke detected alarm because they’re busy repeating for a light switch somewhere.
And yes to the second question as long as the battery powered device is also zwave, just run a zwave repair utility after you install the mains powered device to refresh your network.
See the FAQ in the community-created wiki. 
http://thingsthataresmart.wiki/index.php?title=Is_this_device_a_repeater%3F
Thanks
When I am buying one how do I know if it will act as a repeater?
Is there something I need to look for in particular?
You can check the conformance statement at the official zwave alliance site (repeaters are also called “routing slaves”).
https://products.z-wavealliance.org
But usually the manufacturer will call it out in the product description.
