Set a attribute value for climate

Folks,
I do have
entity_id=climate.buro_thermostat

and need to (snipe form the log)
new_state=<state climate.buro_thermostat=auto

Nov 26 11:23:24 home-assistant hass[9428]: 2017-11-26 11:23:24 INFO (MainThread) [homeassistant.core] Bus:Handling <Event state_changed[L]: entity_id=climate.buro_thermostat, new_state=<state climate.buro_thermostat=auto; current_temperature=17.4, operation_mode=auto, friendly_name=Büro Thermostat, temperature=18.0, max_temp=25.0, operation_list=[‘auto’, ‘manual’, ‘boost’, ‘vacation’], min_temp=4.5, unit_of_measurement=°C @ 2017-11-26T11:23:24.155096+01:00>, old_state=<state climate.buro_thermostat=manual; current_temperature=0.0, operation_mode=manual, friendly_name=Büro Thermostat, temperature=18.0, max_temp=25.0, operation_list=[‘auto’, ‘manual’, ‘boost’, ‘vacation’], min_temp=4.5, unit_of_measurement=°C @ 2017-11-26T11:20:15.107956+01:00>>

I created an an automation and the action looks like:

action:
   - service: climate.set_temperature
     data:
        entity_id: climate.buro_thermostat
        operation_mode: auto

this seems not to cause my MAX do update it’s operation mode to auto. Still keeps as it is.
Can anybody help.

How would this work when I would like to increase my manual temp to 20Grad?