Upon arrival the customers thermostat was not connecting to the internet. I went down and reset the on/off which at the furnace. Waited 10 minutes for the stat to reboot but it never did. Found out the stat had gone bad. They don’t make the stat they had so I got them the Lennox S40 with temp sensor for upstairs. The sensor for upstairs was not compatible with the Lennox S40 so I went back to Lennox to get the correct sensor for upstairs. I picked up the Lennox zoning extender and installed it upstairs. I then made sure both of the homeowners cell phones could connect and control the thermostat. It is working properly at this time! Have a great day!