Generic thermostat config not working : tried it all

Dealing with zone valves for radiant heating:

I realize generic thermostat cannot switch two entities on, so I set up a group:

 living_room_heater:
      name: living_room_heat
      entities:
      - switch.relay_channel_2
      - switch.relay_channel_3
Then set it up like this:

climate:
  - platform: generic_thermostat
    name: Family room (downstairs)
    heater: 
      group: living_room_heater
    target_sensor: sensor.lumi_lumi_weather_12114a04_temperature
    min_temp: 65
    max_temp: 75
    hot_tolerance: 0.5
    ac_mode: false
    initial_hvac_mode: heat

So when I check config before restart, I get this :

Invalid config for [climate.generic_thermostat]: value should be a string for dictionary value @ data[‘heater’]. Got OrderedDict([(‘group’, ‘living_room_heater’)]). (See ?, line ?).
Invalid config for [climate.generic_thermostat]: string value is None for dictionary value @ data[‘name’]. Got None. (See ?, line ?)

At a loss, it worked previously…

The heater option requires an entity that can be switched on/off.

Did this fail to work for you?

    heater: group.living_room_heater

Thank you.