Despite other reviews there are multiple ways to setup control of the thermostat. I had it working from two iPhones , the web browser and HomeAssistant Thermostat card in under an hour. Then it quit working 30 days later. 2,5 hrs of futzing around and was never able to re-initialize the thermostat. i was able to restart it an was rewarded with occasionally it might respond to a request after way more than the 5 minutes allowed or remote connections except this was all local connections on a very done Unifi network. At some point, my lucky charm, my beautiful spouse, walked through the room and listened to my complaints and it started working.I pointed out there are numerous options to connect devices to RadoTherm but....... a bucket of Peyote puke on a roller coaster is better organized. If you have issues, even after I made a matrix of options t try, I spent 2,5 hours trying to change the program from AC to Auto and have no idea why it started working other than, I'm pretty sure, it was because my spouse walked though the room.My advice to HA geeks is to build you own for a few bucks and download one of many sketches. If your not willing to do that, buy a Nest or any other Best Buy, Lowes, etc offering.if they reply to my support email, I will update this postI got how to reset the thermostat from RadioTherm. But not clear on how to re-add it to the iPhone. I did it but it was after lots of fuddling and in a slightly cold house -Hi,Please make sure of the following:If you remove the batteries from the unit for 5 minutes does it continue to operate?When you press the reset button what color light do you get?If you get a yellow light is there a 5 digit pin in the top left corner?Does your WiFi router support 802.11G?If the answers to all of the above questions is yes then it is ready for set up.Please do the following:Reset ThermostatPress menuPress and hold the center of the screen until you see 00 or 01 or 02 and arrow keysPress the up arrow keyThe unit will count down from 9Wait till it goes back to the main screenWiFi ResetPress menuPress and hold the center of the screen until you see 00 or 01 or 02 and arrow keysPress the down arrow keyThe unit will count down from 5It will then start blinking the amber light and give you a new provisioning pin (note this may take a minute) Once reset it is best if you leave the unit alone for 20 minutes so the WiFi module can run a self test.Next if you have an iOS device, like and iPhone go to the Wi-Fi enabled Radio Thermostat app and click on the plus to add the thermostat. Then follow the onscreen instructions.When connecting to the thermostat network verify that you are connected before going back to the app. To do this press the info icon and the router IP should be 192.168.10.1 if it is not then the phone is not connected to the thermostat network -- if that happens try disconnecting from the thermostat network and connect to a different network. Then try it again. If it still is not working turn off the device and turn it back on and try again.I have also attached the detail instructions for the iPhone.I chgd my review to 3 Stars. The thermostat itself has worked well since I quit using the RT apps. I have setup HomeAssistant location services and control thevThermostat from there and the HA app. That’s what I bought it for. If you want to use their apps alone that might work. Please post a review if you try it.This thermostat had potential. Although the manual specially says that the thermostat will work without a 'C' wire (and it actually does, but NOT suggested!), I took the time to re-run all new thermostat wire and included the 'C' wire from the HVAC unit. Here's the kicker. Even with a 40VA transformer, it was NOT enough power to run the wi-fi side. The HVAC unit did not have enough power while running the igniter (GAS) to initiate the fire process, and HVAC board would go into error mode. Was it the Thermostat or the wiring? Well, as soon as I unhooked the 'C' wire that was ONLY feeding the thermostat, presto, everything worked fine, except then you're 100% on battery power. That was the drawback ...I purchased the particular thermostat because of the API, so I could locally log/control the thermostat (Which indeed, did work fine as expected). However, hitting the thermostat via wifi on batteries only, no-go. It quickly ran down the batteries and negated the whole point of the purchase.I did pop out the included (removable) wifi card, making it a dumb thermostat, and hooked back up the 'C' wire, and the HVAC unit worked as it should. So I narrowed it down the power consumption of the wifi card.It works fine as long as the HVAC unit doesn't try to fire a gas igniter, while the wifi is in use. When it does, the wifi drops out and disconnects, and the igniter fails to light the gas.However ... Being that the firmware was dated March 22,2012, and no newer firmware has been released since, I highly doubt Radio Thermostat will updating the design or product specs. It's a shame, since I have since designed my own thermostat using a ESP8266 board, which draws MUCH less power and have created my own front end and back end specific to my wants, not by outdated 2012 specs.Final thoughts, great concept and idea, but for something that's 8+ years old ... move on and don't waste your time and effort to try to make this work, it probably wont.