Update on my original post. I did buy the thermostat from Lowes which is part of their home automation system called Iris. I originally liked it, although to get all the advantages I had to get their service at $10/month. I could track my temperature usage using my iPhone or my desktop computer. Then, about a year later, they discontinued the model of hub and sent me a new one (for free). I am very dissatisfied with the new service, it won't work with the desktop computer. But, most of all, their service is very poor. When I call, it may take an hour or more on hold before I get someone, and the most that person will give me is "I don't know". Before I switched hubs, I needed another WiFi thermostat for my new vacation home, so I got another Iris one, this time with the same, lame hub. Same problems and, in addition, the thermostat itself failed with no compensation from Lowes. The heating installer recommended a Honeywell 9000 series, which he got and installed. It works very well, so when I needed another Tstat for another zone, I got another and installed it myself (the box says "Pro", but I had no problem). Honeywell has a nice free service (mytotalconnectcomfort) which keeps track of my heating and if the tstat fails to connect, I get periodic messages telling me so (usually this is caused by either a router/cable-supplied internet failure or a power failure). I'm thinking about replacing my Iris tstat at my primary residence with the same model Honeywell, just to get the peace of mind of knowing that it's working. The 9000 series Honeywell cost $215, but they have many look-alikes at Home Depot and Lowes for about half that price, and I don't know what the difference is. I would like to have this new one on the same Honeywell as the ones I already have. Any input here?

Hopefully the new modem/router will take care of the problem. I would just use the Built-In Router. Too much of a hassle to try and Disable the Built-In Router! Just make sure you have a Secure Password Set up. You may also want to check around the internet to see if your ISP is trying to pull a Comcast. The New Comcast Modem/Routers are set up to use your modem to share with other Comcast Customers. Comcast doesn't tell you about this but when someone is close to your Network they'll see an Xfinity SSID (Hotspot) that's Unsecured. This person can then use your Connection to access the internet. This connection is separate from the connection you're using that is secured! It's a Dual Band Router and they have it set as a Guest account without your knowledge. Not 100% sure but I believe you must be a Comcast Customer to be able to use this Guest account (think they'll ask for your Comcast Info). Here is a link that can tell you about what Comcast has done: Xfinity WiFi, and how to shut this feature off! You don't have to let your modem broadcast a Hotspot! I haven't had very good luck with the New Modem/Routers (keep dropping connections) so I just have a Modem and I use my own Router. I have a Linksys EA6400 Dual Band Router and I have a Guest Account set with an easy to remember Password. The other Account Password is much harder to remember. I use the Guest Account forthe Guests at my house! Everyone always asks right away, what's your password? They want to connect their Phones, Tablets and Laptops!

I just saw your comment, thanks!, and was researching other symptoms that I discovered 2 days ago. I can no longer connect to the Internet from the laptop (Windows 10) but still see networks listed on the laptop when I ask it to show all networks. When I go into 'Manage known networks', only one of my two networks will display (I also see other neighbor's networks) but my tablet works fine and displays both of my networks. I have moved the laptop to other locations in the house but no change. My network listed is set to 'connect automatically when in range'. Airplane Mode is off. Oddly, the base of the laptop has a light with a WiFi symbol that is currently lit orange. The online documentation on the PC does not say what the orange light means. Q. so how do I check my W10 updates? Ever since Windows upgraded from W7, I have no idea where things are any more. ;o( Q. what is a wifi analyzer? and what is a wifi adapter? what does one do with them? take them to a PC Service Shop to take the laptop's old analyzer and adapter and install the new ones on the laptop? Q. what am I looking for... in the utilities link? I looked in the network tools (I assume that is what you were suggesting). Thanks

I had the same experience not too long ago, it may have been at the same time as you mention. For whatever reason, the Resideo (operating as Honeywell home or some such) seems to have a fragile network setup. It hiccups sometimes. Outages are never too long. The good news is, the thermostats operate normally and follow the previously entered settings with or without a connect to the internet. What's lost with a hiccup is the ability to CHANGE the existing settings - whether it's the temperature, the schedule, or to put on or take off a Hold. As above, I have them in two different locations (separated by hundreds of miles). A few times when the power has gone off at the location I'm absent from, when the power has come back on, the thermostats have been able to reestablish internet connections once the infrastructure (the modem and router providing the Wifi signal) are back on. In one location, it's a Redlink system and a return from a power outage involves an extra step. There's is a separate, standalone internet gateway that connects to the router on one side and then provides Redlink RF transmit/receive traffic on the other. It's the Redlink signal from this Resideo/Honeywell gateway that the thermostat connects with, not a Wifi signal. I wouldn't be concerned about it. It happens every now and again, not that frequently and never of long duration. I find the same is true with other internet sites for businesses I'm a customer of or other sites I interact with. Sometimes, I just can't log in or continue a session because of what appears to be a problem on the other side. I think it's to be expected.