Replacing your Kidde VS2-G-SP with a Kidde VS4-G should be a straightforward process since they both belong to the same product line and are designed to work with each other seamlessly. The VS4-G, being a four-loop system with one 250-point loop installed, offers enhanced capabilities compared to the VS2-G-SP, making it a suitable upgrade. Just ensure that the power requirements and wiring configurations match, and you should be good to go. If you have any specific concerns or questions during the replacement process, feel free to reach out, and we’ll be happy to assist you further.