In most cases, Smart Home devices will continue to operate normally and provide their intelligent functions to the systems they control. Fortunately, a home’s wireless network is independent upon an Internet connection. This means, even if you don’t have a connection to an Internet Service Provider or if an Internet disconnection were to occur, your home’s wireless network would continue allowing devices on that network to communicate with each other.
Unfortunately, accessing your system from a remote location using an app will require an Internet connection in order to access your home’s wireless network if you’re not in range of the network. It is important to note that any smart home device with a feature that requires information from a third party source over the Internet would also be unable to access that information.
A smart thermostat, for instance, is hardwired directly to your furnace and A/C just like a traditional thermostat would be. As a result, even without a connection to a WiFi network or an Internet connection, the thermostat can continue working as expected using features that are not reliant on those connections. Features like changing the temperature of your home a phone app or the thermostat accessing weather reports might have limited functionality.