w.Intercom = i;New Tado not giving heat, as previous system — tado° Community

New Tado not giving heat, as previous system

I've just installed the Tado V3+ wireless system, replacing my existing programmer.
The app, wireless thermostat and receiver all say everything is working, BUT THERE IS NO CALL FOR HEAT. I wired everything per the instructions (they are really simple to understand) so don't know how I can suddenly have no hot water or heating!