Sync TRV's in automation. Get an error

Have 3 radiators in a room. Want to sync them together.

Got the following automation

- id: 'trv_zal_sync'
  alias: TRV Sync
  description: 'TRV Sync'
  trigger:
  - platform: state
    entity_id:
    - climate.trv_1_kitchen
    attribute: temperature
  condition: []
  action:
  - service: climate.set_temperature
    target:
      entity_id:    
      - climate.trv_1_zal_left
      - climate.trv_1_zal_right
    data_template:
       temperature: ' {{ states.climate.trv_1_kitchen.attributes.temperature | int }}'
  mode: single

which throws the following error

script. Unexpected error for call_service at pos 1: Z-Wave error 1405: The node failed to decode the message. (ZW1405)
Traceback (most recent call last):