Nobody is going to be clicking on some air frequency to control his central heating. And if he really wanted to, nobody could stop him;
Read through that again slowly. It is a logical nonsense.
Beyond that, your airy dismissal of the law on the basis that "no one can stop them" (Oh really? Why not?) is in diametric contradiction to your assumption that nothing can be done because of some completely fictitious "liability".
Sorry you seem to swallow all that twaddle about liability, it's one of the worst diseases crippling our society at present. One day we'll realise that even lawyers can't do things that are beyond their powers and we can all get on with the rest of our lives unhindered by imaginary and self-imposed restrictions. May it come soon.
As I suggested above, had you troubled to read it, the CAA do not regulate the electromagnetic spectrum. Surprise-Surprise OFCOM do that! The restriction below is neither imaginary nor imposed by the CAA.
UK Interface Requirement 2052
See table 3.1, elements 3 and 4
That's where it says PCL isn't licenced here.