diff --git a/homeassistant/components/google_assistant/smart_home.py b/homeassistant/components/google_assistant/smart_home.py
index cd1583fb377..634d5074a0e 100644
--- a/homeassistant/components/google_assistant/smart_home.py
+++ b/homeassistant/components/google_assistant/smart_home.py
@@ -124,14 +124,15 @@ def entity_to_device(entity: Entity, units: UnitSystem):
 
     if entity.domain == climate.DOMAIN:
         modes = ','.join(
-            m for m in entity.attributes.get(climate.ATTR_OPERATION_LIST, [])
-            if m in CLIMATE_SUPPORTED_MODES)
+            m.lower() for m in entity.attributes.get(
+                climate.ATTR_OPERATION_LIST, [])
+            if m.lower() in CLIMATE_SUPPORTED_MODES)
         device['attributes'] = {
             'availableThermostatModes': modes,
             'thermostatTemperatureUnit':
             'F' if units.temperature_unit == TEMP_FAHRENHEIT else 'C',
         }
-
+        _LOGGER.debug('Thermostat attributes %s', device['attributes'])
     return device
 
 
@@ -143,7 +144,7 @@ def query_device(entity: Entity, units: UnitSystem) -> dict:
             return None
         return round(METRIC_SYSTEM.temperature(deg, units.temperature_unit), 1)
     if entity.domain == climate.DOMAIN:
-        mode = entity.attributes.get(climate.ATTR_OPERATION_MODE)
+        mode = entity.attributes.get(climate.ATTR_OPERATION_MODE).lower()
         if mode not in CLIMATE_SUPPORTED_MODES:
             mode = 'on'
         response = {
@@ -218,6 +219,7 @@ def determine_service(
     Attempt to return a tuple of service and service_data based on the entity
     and action requested.
     """
+    _LOGGER.debug("Handling command %s with data %s", command, params)
     domain = entity_id.split('.')[0]
     service_data = {ATTR_ENTITY_ID: entity_id}  # type: Dict[str, Any]
     # special media_player handling
@@ -260,7 +262,6 @@ def determine_service(
         service_data['brightness'] = int(brightness / 100 * 255)
         return (SERVICE_TURN_ON, service_data)
 
-    _LOGGER.debug("Handling command %s with data %s", command, params)
     if command == COMMAND_COLOR:
         color_data = params.get('color')
         if color_data is not None: