diff --git a/wideq/ac.py b/wideq/ac.py
index 63542e8..a9afaf5 100644
--- a/wideq/ac.py
+++ b/wideq/ac.py
@@ -4,6 +4,7 @@ import enum
 
 from .client import Device
 from .util import lookup_enum
+from .core import FailedRequestError
 
 
 class ACVSwingMode(enum.Enum):
@@ -257,8 +258,11 @@ class ACDevice(Device):
     def get_volume(self):
         """Get the speaker volume level."""
 
-        value = self._get_control('SpkVolume')
-        return int(value)
+        try:
+            value = self._get_control('SpkVolume')
+            return int(value)
+        except FailedRequestError:
+            return 0  # Device does not support volume control.
 
     def poll(self):
         """Poll the device's current state.
diff --git a/wideq/core.py b/wideq/core.py
index da868b0..993ca62 100644
--- a/wideq/core.py
+++ b/wideq/core.py
@@ -67,16 +67,10 @@ class APIError(Exception):
 class NotLoggedInError(APIError):
     """The session is not valid or expired."""
 
-    def __init__(self):
-        pass
-
 
 class NotConnectedError(APIError):
     """The service can't contact the specified device."""
 
-    def __init__(self):
-        pass
-
 
 class TokenError(APIError):
     """An authentication token was rejected."""
@@ -85,6 +79,16 @@ class TokenError(APIError):
         pass
 
 
+class FailedRequestError(APIError):
+    """A failed request typically indicates an unsupported control on a
+    device.
+    """
+
+
+class InvalidRequestError(APIError):
+    """The server rejected a request as invalid."""
+
+
 class MonitorError(APIError):
     """Monitoring a device failed, possibly because the monitoring
     session failed and needs to be restarted.
@@ -95,6 +99,14 @@ class MonitorError(APIError):
         self.code = code
 
 
+API_ERRORS = {
+    "0102": NotLoggedInError,
+    "0106": NotConnectedError,
+    "0100": FailedRequestError,
+    9000: InvalidRequestError,  # Surprisingly, an integer (not a string).
+}
+
+
 def lgedm_post(url, data=None, access_token=None, session_id=None):
     """Make an HTTP request in the format used by the API servers.
 
@@ -125,10 +137,8 @@ def lgedm_post(url, data=None, access_token=None, session_id=None):
         code = out['returnCd']
         if code != '0000':
             message = out['returnMsg']
-            if code == "0102":
-                raise NotLoggedInError()
-            elif code == "0106":
-                raise NotConnectedError()
+            if code in API_ERRORS:
+                raise API_ERRORS[code](code, message)
             else:
                 raise APIError(code, message)