diff --git a/miio/airpurifier.py b/miio/airpurifier.py
index b6b9a35f5..42a3a100d 100644
--- a/miio/airpurifier.py
+++ b/miio/airpurifier.py
@@ -109,9 +109,12 @@ def illuminance(self) -> Optional[int]:
         return self.data["bright"]
 
     @property
-    def buzzer(self) -> bool:
+    def buzzer(self) -> Optional[bool]:
         """Return True if buzzer is on."""
-        return self.data["buzzer"] == "on"
+        if self.data["buzzer"] is not None:
+            return self.data["buzzer"] == "on"
+
+        return None
 
     @property
     def child_lock(self) -> bool:
@@ -279,4 +282,7 @@ def set_child_lock(self, lock: bool):
 
     def set_volume(self, volume: int):
         """Set volume of sound notifications [0-100]."""
+        if volume < 0 or volume > 100:
+            raise AirPurifierException("Invalid volume: %s" % volume)
+
         return self.send("set_volume", [volume])
diff --git a/miio/tests/test_airpurifier.py b/miio/tests/test_airpurifier.py
index 48069b110..94c2a55aa 100644
--- a/miio/tests/test_airpurifier.py
+++ b/miio/tests/test_airpurifier.py
@@ -23,9 +23,10 @@ def __init__(self, *args, **kwargs):
             'f1_hour': 3500,
             'led': 'off',
             'led_b': 2,
-            'bright': None,
+            'bright': 83,
             'buzzer': 'off',
-            'child_lock': 'off'
+            'child_lock': 'off',
+            'volume': 50,
         }
         self.return_values = {
             'get_prop': self._get_state,
@@ -37,6 +38,7 @@ def __init__(self, *args, **kwargs):
             'set_level_favorite':
                 lambda x: self._set_state("favorite_level", x),
             'set_led_b': lambda x: self._set_state("led_b", x),
+            'set_volume': lambda x: self._set_state("volume", x),
         }
         super().__init__(args, kwargs)
 
@@ -91,6 +93,8 @@ def test_status(self):
         assert self.state().led_brightness == LedBrightness(self.device.start_state["led_b"])
         assert self.state().buzzer == (self.device.start_state["buzzer"] == 'on')
         assert self.state().child_lock == (self.device.start_state["child_lock"] == 'on')
+        assert self.state().illuminance == self.device.start_state["bright"]
+        assert self.state().volume == self.device.start_state["volume"]
 
     def test_set_mode(self):
         def mode():
@@ -117,6 +121,7 @@ def favorite_level():
         self.device.set_favorite_level(6)
         assert favorite_level() == 6
         self.device.set_favorite_level(10)
+        assert favorite_level() == 10
 
         with pytest.raises(AirPurifierException):
             self.device.set_favorite_level(-1)
@@ -141,7 +146,6 @@ def test_set_led(self):
         def led():
             return self.device.status().led
 
-        # The LED brightness of a Air Purifier Pro cannot be set so far.
         self.device.set_led(True)
         assert led() is True
 
@@ -168,24 +172,50 @@ def child_lock():
         self.device.set_child_lock(False)
         assert child_lock() is False
 
-    def test_status_without_led_b_and_with_bright(self):
-        self.device._reset_state()
+    def test_set_volume(self):
+        def volume():
+            return self.device.status().volume
+
+        self.device.set_volume(0)
+        assert volume() == 0
+        self.device.set_volume(35)
+        assert volume() == 35
+        self.device.set_volume(100)
+        assert volume() == 100
+
+        with pytest.raises(AirPurifierException):
+            self.device.set_volume(-1)
 
-        self.device.state["bright"] = self.device.state["led_b"]
-        del self.device.state["led_b"]
+        with pytest.raises(AirPurifierException):
+            self.device.set_volume(101)
+
+    def test_status_without_volume(self):
+        self.device._reset_state()
 
-        assert self.state().led_brightness == LedBrightness(
-            self.device.start_state["led_b"])
+        # The Air Purifier 2 doesn't support volume
+        self.device.state["volume"] = None
+        assert self.state().volume is None
 
-    def test_status_without_led_brightness_at_all(self):
+    def test_status_without_led_brightness(self):
         self.device._reset_state()
 
+        # The Air Purifier Pro doesn't support LED brightness
         self.device.state["led_b"] = None
-        self.device.state["bright"] = None
         assert self.state().led_brightness is None
 
     def test_status_without_temperature(self):
         self.device._reset_state()
         self.device.state["temp_dec"] = None
-
         assert self.state().temperature is None
+
+    def test_status_without_illuminance(self):
+        self.device._reset_state()
+        # The Air Purifier 2 doesn't provide illuminance
+        self.device.state["bright"] = None
+        assert self.state().illuminance is None
+
+    def test_status_without_buzzer(self):
+        self.device._reset_state()
+        # The Air Purifier Pro doesn't provide the buzzer property
+        self.device.state["buzzer"] = None
+        assert self.state().buzzer is None