I am planning to upgrade my Honeywell controlled heating system to Evohome and am trying to work out which of the components in my current setup will be compatible with the Evohome controller.

The current setup is based on a Grant Vortex Eco-Utility oil-fired boiler; the heating circuit has two number motorised zone valves supplying the ground floor and upper floors respectively. Each zone valve is wired to an HC60NG relay module. The ground floor relay module is bound to two CM67z controllers, each one controlling two room zones with HR80UK radiator controllers on each radiator (6 number in all in 4 rooms). The upstairs relay module is bound to a single CM927 controller. The upstairs radiators (8 number in total in 6 rooms) have traditional thermostatic radiator valves (Pegler Terrier IIs) so the entire upstairs zone is either on or off.

What I want to do is replace all the controllers with a single Evohome controller and add wireless radiator controllers upstairs (HR92) on all radiators so all rooms in the house can be fully controlled by the Evohome (10 rooms in total with 14 wireless radiator controllers).

What I would like to know is: (i) will the Evohome controller work with my existing two number HC60NG relay modules or do these need replacing with the BDR91 wireless relay boxes? (ii) can I continue to use the HR80UK radiator controllers on the ground floor alongside the new HR92 radiator controllers on the upstairs floors? (iii) any other compatibility issues?

Many thanks.