I need to keep the teenagers from messing with the control unit

My sibling as well as her teenagers started living with myself and others recently.

It is a long story as well as 1 I don’t really want to get into, and what you should take away from it is that I am ecstatic to have them as well as that they are welcome to stay as long as they need to.

I am just glad I have the extra room. There is only 1 problem: the teenagers keep messing with the control unit. It must be them. Who else would turn the cooling system down to 40 degrees 1 afternoon then up to 140 the next? I don’t want to say anything to my sibling because I want her to know welcome. I want the teenagers to know they are in a safe place too. That is why I am getting a smart control component installed. The HVAC tech is coming out on Sunday to install it for me. I understand that smart control units are simple to install yourself but I am not handy at all. I hardly own any tools as well as I don’t understand technology. I genuinely won’t be able to program the current smart control component to my HVAC method myself, let alone program the password or anything like that. That is what I pay the HVAC professional for, and once the smart control component is passworded then I will be able to keep the rapidly adjusting temperatures in the home set to a comfortable 76 degrees. The teenagers can touch it however it won’t do anything. It is not as though I don’t want them to be comfortable. I genuinely do. I just don’t want them playing with the temperature settings. That ends up costing myself and others money. If they end up staying a long time I might guess about getting zone control installed too; But, 1 thing at a time.