OK, one last part of the saga in Hive Home forcing me to buy a new hub, and hiding behind data privacy as a reason for not allowing me to use the perfectly functional one I have already. I sent them this e-mail last week:

Hi there,  

I was told by a member of your technical support team today that I would  not be able to use the Hive hub installed in the house I recently  bought. Apparently this is because Hive does not allow a hub to be  resold or passed on, but effectively locks it to one consumer for life,  requiring me to buy a whole new hub.  How would I go about recycling or having you reuse (and potentially  resell) the existing locked hub? I'm hopeful that you have a better  solution than taking it to a household recycling site, as I noticed on  the Hive website that the Hub conforms to the WEEE Directive:  https://www.hivehome.com/img/attachments/Declaration_of_Conformity_Hive_Nanohub_2.pdf

Today I got this response:

I hope this finds you well and my sincerest apologies for the length of time it has taken us to get back in touch.  

I am really sorry but the adviser you spoke with on the phone was correct. We wouldn't be able to remove this from the current owners account as it holds their personal data. They should take this with them when they leave the property and they are the only people who would be able to get use out of the hub.  

If the previous owners have not contacted you to look for this hub, then I would advise you take this to a household recycling site.  My apologies that I could not be of any further assistance  

Many thanks.

Sigh. If I'm reading the WEEE Directive correctly, it's Hive's responsibility to provide a free recycling service and not pass the burden on to the local council. Even better would be to wipe the data from the hub and re-use/re-sell it, given the environmental cost of the device. And let's be honest: Who would design and sell a hub that cannot be factory reset?