Having changed router my wifi dongle will not connect.
All recommendation have been followed including reformatting dongle with Fat 32.
Now I am unable to go further as when I type in :10.10.100.254 all that I get is 'bad gateway' or 'This site can't be reached as it took too long to respond'.
WiFi Dongle

Why would you re-format the dongle? The USB stick in it is not related in any way to the Dongle as a wifi connection for your Inverter. If you didnt backup the MSN.txt file on it, you now need to get GivEnergy involved, this file is needed
On teh bottom is a cap, remove it, and hold the the button in for 10s to reset the Dongle software.

martinhort if you've changed your router the easiest way to get everything working again is the have your network name and password the same as the old router.

Cdent I have just replaced my router. I changed my router name and wi-fi password to macth the old one and I had no problems at all. Worked like a dream.

Stevef1964 yep, also saves you having to reconnect all other devices, not just your inverter!

and means you do not have to re learn a new wifi password. google can continue spying on me..JOKE!