v2/v3/v3+ upgrade question
I've recently started to replace a number of thermostats in my house with Tado room thermostats. I have underfloor heating all downstairs with wired thermostats controlling 5 rooms. Upstairs I have a single hallway thermostat and radiator valves in the bedrooms (upstairs is a separate heating circuit).
I've now have 4 thermostats and 3 radiator valves and the system uses a v3+ hub. As I bought a lot of the extra thermostats of ebay and shpock I have a few left over hubs including the old v2 hub.
Now, I didn't do a lot of research regarding the services but a Tado rep tells me that I can upgrade from the v2 hub to the latest and get all the benefits of the paid for service for a one off fee of 19.99. I cannot do that as my hub is v3+. However, I do have a V2 hub so could I swap my hubs over just to then upgrade for 19.99? If this is possible, then what do I need to do in order to achieve this (deregister all devices first for example)