The HR80 is the predecessor of the HR92. The HR80 radiator valve was released with the first generation Evohome. However, you can assign the HR80 to the latest version of the Evohome (Evohome Wi-Fi). Take note, the configuration of the button is slightly different from the HR92.
If you still have an older version of the Evohome (Evohome 1st generation with black and white screen or the Evotouch Color) then you cannot assign HR92 to the controller in the event of a defective HR80. The HR92 can only be assigned to the latest version of Evohome (Wi-Fi).