diff --git a/tests/components/tradfri/conftest.py b/tests/components/tradfri/conftest.py
index 32c4b74e8a5..d0e6c935822 100644
--- a/tests/components/tradfri/conftest.py
+++ b/tests/components/tradfri/conftest.py
@@ -2,12 +2,20 @@
 from __future__ import annotations
 
 from collections.abc import Generator
+import json
+from typing import Any
 from unittest.mock import MagicMock, Mock, patch
 
 import pytest
+from pytradfri.device import Device
+from pytradfri.device.air_purifier import AirPurifier
+
+from homeassistant.components.tradfri.const import DOMAIN
 
 from . import GATEWAY_ID, TRADFRI_PATH
 
+from tests.common import load_fixture
+
 
 @pytest.fixture
 def mock_gateway_info():
@@ -79,3 +87,18 @@ def mock_api_factory(mock_api) -> Generator[MagicMock, None, None]:
         factory.init.return_value = factory.return_value
         factory.return_value.request = mock_api
         yield factory.return_value
+
+
+@pytest.fixture(scope="session")
+def air_purifier_response() -> dict[str, Any]:
+    """Return an air purifier response."""
+    return json.loads(load_fixture("air_purifier.json", DOMAIN))
+
+
+@pytest.fixture
+def air_purifier(air_purifier_response: dict[str, Any]) -> AirPurifier:
+    """Return air purifier."""
+    device = Device(air_purifier_response)
+    air_purifier_control = device.air_purifier_control
+    assert air_purifier_control
+    return air_purifier_control.air_purifiers[0]
diff --git a/tests/components/tradfri/test_diagnostics.py b/tests/components/tradfri/test_diagnostics.py
index 2b400cb39bb..a30b75147ca 100644
--- a/tests/components/tradfri/test_diagnostics.py
+++ b/tests/components/tradfri/test_diagnostics.py
@@ -1,55 +1,32 @@
 """Tests for Tradfri diagnostics."""
-from unittest.mock import MagicMock, Mock, PropertyMock, patch
+from __future__ import annotations
 
-import pytest
+from unittest.mock import MagicMock, Mock
+
+from pytradfri.device.air_purifier import AirPurifier
 
 from homeassistant.core import HomeAssistant
 
 from .common import setup_integration
-from .test_sensor import mock_fan
 
 from tests.components.diagnostics import get_diagnostics_for_config_entry
 from tests.typing import ClientSessionGenerator
 
 
-@pytest.fixture(autouse=True)
-def setup(request):
-    """Set up patches for pytradfri methods for the fan platform.
-
-    This is used in test_fan as well as in test_sensor.
-    """
-    with patch(
-        "pytradfri.device.AirPurifierControl.raw",
-        new_callable=PropertyMock,
-        return_value=[{"mock": "mock"}],
-    ), patch(
-        "pytradfri.device.AirPurifierControl.air_purifiers",
-    ):
-        yield
-
-
 async def test_diagnostics(
     hass: HomeAssistant,
     hass_client: ClientSessionGenerator,
     mock_gateway: Mock,
     mock_api_factory: MagicMock,
+    air_purifier: AirPurifier,
 ) -> None:
     """Test diagnostics for config entry."""
-    mock_gateway.mock_devices.append(
-        # Add a fan
-        mock_fan(
-            test_state={
-                "fan_speed": 10,
-                "air_quality": 42,
-                "filter_lifetime_remaining": 120,
-            }
-        )
-    )
+    device = air_purifier.device
+    mock_gateway.mock_devices.append(device)
+    config_entry = await setup_integration(hass)
 
-    init_integration = await setup_integration(hass)
-
-    result = await get_diagnostics_for_config_entry(hass, hass_client, init_integration)
+    result = await get_diagnostics_for_config_entry(hass, hass_client, config_entry)
 
     assert isinstance(result, dict)
     assert result["gateway_version"] == "1.2.1234"
-    assert result["device_data"] == ["model"]
+    assert result["device_data"] == ["STARKVIND Air purifier"]
diff --git a/tests/components/tradfri/test_fan.py b/tests/components/tradfri/test_fan.py
index 60a38e06f0c..606afed77ce 100644
--- a/tests/components/tradfri/test_fan.py
+++ b/tests/components/tradfri/test_fan.py
@@ -1,7 +1,6 @@
 """Tradfri fan (recognised as air purifiers in the IKEA ecosystem) platform tests."""
 from __future__ import annotations
 
-import json
 from typing import Any
 from unittest.mock import MagicMock, Mock
 
@@ -12,7 +11,6 @@ from pytradfri.const import (
     ATTR_REACHABLE_STATE,
     ROOT_AIR_PURIFIER,
 )
-from pytradfri.device import Device
 from pytradfri.device.air_purifier import AirPurifier
 
 from homeassistant.components.fan import (
@@ -26,7 +24,6 @@ from homeassistant.components.fan import (
     SERVICE_TURN_OFF,
     SERVICE_TURN_ON,
 )
-from homeassistant.components.tradfri.const import DOMAIN
 from homeassistant.const import (
     ATTR_SUPPORTED_FEATURES,
     STATE_OFF,
@@ -37,23 +34,6 @@ from homeassistant.core import HomeAssistant
 
 from .common import setup_integration, trigger_observe_callback
 
-from tests.common import load_fixture
-
-
-@pytest.fixture(scope="module")
-def air_purifier_response() -> dict[str, Any]:
-    """Return an air purifier response."""
-    return json.loads(load_fixture("air_purifier.json", DOMAIN))
-
-
-@pytest.fixture
-def air_purifier(air_purifier_response: dict[str, Any]) -> AirPurifier:
-    """Return air purifier."""
-    device = Device(air_purifier_response)
-    air_purifier_control = device.air_purifier_control
-    assert air_purifier_control
-    return air_purifier_control.air_purifiers[0]
-
 
 async def test_fan_available(
     hass: HomeAssistant,