@MrTedd 

Hi, sir, please don't worry. We will try our best to help you identify and solve the issue.

As your description that both extenders show 3 lights: power, house, Wi-Fi, it seems that the extenders are working fine.

Since you only press pair button to set up the extender, the extenders may keep its default Wi-Fi name which begins with TP-Link.

You can check the white label printed on the back of the two extenders.

The SSID (Wi-Fi name) and wireless password is printed there. You can check if you can see the Wi-Fi name and if you can get internet from it.

If you can, it means all the powerline devices are working well. You can move the two extenders to another places where you want the internet.

Actually, we have the software tpPLC utility. You can download it on your PC and can manage all the powerline units very easily.

You can check it from this link. https://www.tp-link.com/support/download/tl-wpa4220t-kit/#Utility

We also have the APP which lets you conveniently view and manage your TP-Link powerline devices via your smart device. 

https://www.tp-link.com/support/download/tl-wpa4220t-kit/#Apps

Hope this answer can help you!

If not, please also tell us the correct model number of your device since AV600 is not the correct one and your issue in detail.

Good day!