diff --git a/tests/components/evohome/snapshots/test_water_heater.ambr b/tests/components/evohome/snapshots/test_water_heater.ambr
index ccef7ab3fae..9a42371a1df 100644
--- a/tests/components/evohome/snapshots/test_water_heater.ambr
+++ b/tests/components/evohome/snapshots/test_water_heater.ambr
@@ -1,9 +1,11 @@
 # serializer version: 1
 # name: test_set_operation_mode[default]
   list([
-    tuple(
-    ),
-    tuple(
-    ),
+    dict({
+      'until': datetime.datetime(2024, 7, 10, 12, 0, tzinfo=datetime.timezone.utc),
+    }),
+    dict({
+      'until': datetime.datetime(2024, 7, 10, 12, 0, tzinfo=datetime.timezone.utc),
+    }),
   ])
 # ---
diff --git a/tests/components/evohome/test_water_heater.py b/tests/components/evohome/test_water_heater.py
index b0eaba106a1..5b85a040e4c 100644
--- a/tests/components/evohome/test_water_heater.py
+++ b/tests/components/evohome/test_water_heater.py
@@ -39,7 +39,7 @@ async def test_set_operation_mode(
     freezer: FrozenDateTimeFactory,
     snapshot: SnapshotAssertion,
 ) -> None:
-    """Test SERVICE_SET_OPERATION_MODE of a evohome HotWater entity."""
+    """Test SERVICE_SET_OPERATION_MODE of an evohome DHW zone."""
 
     freezer.move_to("2024-07-10T11:55:00Z")
     results = []
@@ -74,7 +74,9 @@ async def test_set_operation_mode(
 
         assert mock_fcn.await_count == 1
         assert mock_fcn.await_args.args == ()
-        results.append(mock_fcn.await_args.args)
+        assert mock_fcn.await_args.kwargs != {}
+
+        results.append(mock_fcn.await_args.kwargs)
 
     # SERVICE_SET_OPERATION_MODE: on (until next scheduled setpoint)
     with patch("evohomeasync2.hotwater.HotWater.set_on") as mock_fcn:
@@ -90,14 +92,16 @@ async def test_set_operation_mode(
 
         assert mock_fcn.await_count == 1
         assert mock_fcn.await_args.args == ()
-        results.append(mock_fcn.await_args.args)
+        assert mock_fcn.await_args.kwargs != {}
+
+        results.append(mock_fcn.await_args.kwargs)
 
     assert results == snapshot
 
 
 @pytest.mark.parametrize("install", TEST_INSTALLS_WITH_DHW)
 async def test_set_away_mode(hass: HomeAssistant, evohome: EvohomeClient) -> None:
-    """Test SERVICE_SET_AWAY_MODE of a evohome HotWater entity."""
+    """Test SERVICE_SET_AWAY_MODE of an evohome DHW zone."""
 
     # set_away_mode: off
     with patch("evohomeasync2.hotwater.HotWater.reset_mode") as mock_fcn:
@@ -115,7 +119,7 @@ async def test_set_away_mode(hass: HomeAssistant, evohome: EvohomeClient) -> Non
         assert mock_fcn.await_args.args == ()
         assert mock_fcn.await_args.kwargs == {}
 
-    # set_away_mode: off
+    # set_away_mode: on
     with patch("evohomeasync2.hotwater.HotWater.set_off") as mock_fcn:
         await hass.services.async_call(
             Platform.WATER_HEATER,
@@ -134,9 +138,9 @@ async def test_set_away_mode(hass: HomeAssistant, evohome: EvohomeClient) -> Non
 
 @pytest.mark.parametrize("install", TEST_INSTALLS_WITH_DHW)
 async def test_turn_off(hass: HomeAssistant, evohome: EvohomeClient) -> None:
-    """Test SERVICE_TURN_OFF of a evohome HotWater entity."""
+    """Test SERVICE_TURN_OFF of an evohome DHW zone."""
 
-    # Entity water_heater.domestic_hot_water does not support this service
+    # Entity water_heater.xxx does not support this service
     with pytest.raises(HomeAssistantError):
         await hass.services.async_call(
             Platform.WATER_HEATER,
@@ -150,9 +154,9 @@ async def test_turn_off(hass: HomeAssistant, evohome: EvohomeClient) -> None:
 
 @pytest.mark.parametrize("install", TEST_INSTALLS_WITH_DHW)
 async def test_turn_on(hass: HomeAssistant, evohome: EvohomeClient) -> None:
-    """Test SERVICE_TURN_ON of a evohome HotWater entity."""
+    """Test SERVICE_TURN_ON of an evohome DHW zone."""
 
-    # Entity water_heater.domestic_hot_water does not support this service
+    # Entity water_heater.xxx does not support this service
     with pytest.raises(HomeAssistantError):
         await hass.services.async_call(
             Platform.WATER_HEATER,