Alert if thermostat detects temperature out of specified range?

I’m looking for a smart app that can monitor my thermostat at a vacation rental and tell me if the Furnace/AC is broken. Here’s how I envision it would work:

Mode: Cool/Heat
Set Point: temperature set on the thermostat
Current temperature: current ambient temp.
Variance: integer of how far above or below the ambient temp can be away from set point
If ( mode == cool ) {
if ( Current temperature > (Set Point + Variance)) {
Notify user
return;
}
}

if ( mode == heat ) {
if ( Current temperature < (Set Point - Variance)) {
Notify user
return;
}
}

So if you have the heat set to 65 and the ambient temp is now 62, the furnace isn’t doing it’s job and the temp is probably going to keep dropping until you reach some lower temp that then notifies you that you have a freeze condition. Considering it takes time to get a repair guy out to your property to check the furnace, the sooner you know it’s not working, the better.

Same with the AC. If you have it set to 70, it would be nice to know at 75 that it’s just not cooling and you need to take action.

Is there anything like this out there already? I checked the smart apps → create from template and didn’t see anything like that.

I use an Automation to do that for my house, refrigerators and freezers. Here’s one for letting me know it’s too cold in the house:

That won’t work. That’s basically a freeze warning. You can set a notification to be warned at say 50 degrees. However, you won’t get warned that the furnace is broken until it reaches 50 which could be days depending on the starting point and the outside temp. I need to take into account the set temperature and the current temperature not just an absolute. If I have it set to 68, I want to be warned at 65. If I have it set to 60, I want to be warned at 57.

That may be a good use case for webCore. I don’t use it, but it’s worth the effort to investigate.