The 8825 grabs hold of the whole system and does not play well with others, I ran into this on another job. It is used for a maintenance guy to run it. It is very easy to accidentally turn off the heat or to set it to a potentially damaging number, in the north east you do not want to turn the heat off right now. I refused to give a customer the IP address of this device because of the risk of catastrophic potential damage if the home owner goofed up the settings. Other than that it works well.