@jj5724 

Thank you very much. So, I would be looking at $1200 for the S30 plus the work to put it in of up to $450 and then the WiFi would not even be in the S30 but the furnace/AC unit. I am holding on to my thermostat in the hope that that keeps working and the remote control I have to live without for a while which is possible.

@HANSM 

Great. If I had known that, I could have done that too. My internet provider said I didn't have to return their modem and router. Does that mean you had the ability to chose the router names from either the TP-Link A8 in addition to the router names on your old router to hookup  your iComfort Thermostat?

@jj5724 

What I did was to connect the old router with a network cable to one of the ethernet ports of the TPlink. Then I chose it as router on the thermostat but with no other device.

@HANSM I ran into the same problem and found that explicitly setting the A8's Primary and Secondary DNS servers (in Advanced > Network > DHCP Server) fixed it.  I created a free account with OpenDNS and used their DNS server settings.  Hope this helps someone!

Thanks,

Paul

@Paul_in_FL  Thanks much Paul. I am not in that residence but will try it when I get there.

Hans

I just went through a week of back and forth emails with customer service figuring this out. The solution we found for the archer a8 and lennox themostat is changing the DHCP Primary to 8.8.8.8 and secondary to 8.8.4.4

Reconnect the thermostat and it should work.