diff --git a/custom_components/wundasmart/__init__.py b/custom_components/wundasmart/__init__.py
index 81f94d0..d7c75a2 100644
--- a/custom_components/wundasmart/__init__.py
+++ b/custom_components/wundasmart/__init__.py
@@ -95,7 +95,7 @@ async def _async_update_data(self):
         while attempts < max_attempts:
             attempts += 1
 
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 result = await get_devices(
                     session,
                     self._wunda_ip,
diff --git a/custom_components/wundasmart/climate.py b/custom_components/wundasmart/climate.py
index 9e828c9..e07cf00 100644
--- a/custom_components/wundasmart/climate.py
+++ b/custom_components/wundasmart/climate.py
@@ -286,7 +286,7 @@ async def async_added_to_hass(self) -> None:
 
     async def async_set_temperature(self, temperature, **kwargs):
         # Set the new target temperature
-        async with get_session() as session:
+        async with get_session(self._wunda_ip) as session:
             await send_command(
                 session,
                 self._wunda_ip,
@@ -307,7 +307,7 @@ async def async_set_temperature(self, temperature, **kwargs):
     async def async_set_hvac_mode(self, hvac_mode: HVACMode):
         if hvac_mode == HVACMode.AUTO:
             # Set to programmed mode
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,
@@ -323,7 +323,7 @@ async def async_set_hvac_mode(self, hvac_mode: HVACMode):
                     })
         elif hvac_mode == HVACMode.HEAT:
             # Set the target temperature to the t_hi preset temp
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,
@@ -339,7 +339,7 @@ async def async_set_hvac_mode(self, hvac_mode: HVACMode):
                     })
         elif hvac_mode == HVACMode.OFF:
             # Set the target temperature to zero
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,
@@ -367,7 +367,7 @@ async def async_set_preset_mode(self, preset_mode) -> None:
 
             t_preset = float(self.__state[state_key])
 
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,
diff --git a/custom_components/wundasmart/config_flow.py b/custom_components/wundasmart/config_flow.py
index 076a97b..4923971 100644
--- a/custom_components/wundasmart/config_flow.py
+++ b/custom_components/wundasmart/config_flow.py
@@ -32,7 +32,7 @@ def __init__(self, hass, wunda_ip, wunda_user, wunda_pass):
 
     async def authenticate(self):
         """Wundasmart Hub class authenticate."""
-        async with get_session() as session:
+        async with get_session(self._wunda_ip) as session:
             return await get_devices(
                 session,
                 self._wunda_ip,
diff --git a/custom_components/wundasmart/pywundasmart.py b/custom_components/wundasmart/pywundasmart.py
index 3535ba6..25aeb1c 100644
--- a/custom_components/wundasmart/pywundasmart.py
+++ b/custom_components/wundasmart/pywundasmart.py
@@ -11,16 +11,6 @@
 
 DEVICE_DEFS = {'device_sn', 'prod_sn', 'device_name', 'device_type', 'eth_mac', 'name', 'id', 'i'}
 
-_semaphores = {}
-
-def _get_semaphore(wunda_ip):
-    """Return a semaphore object to restrict making concurrent requests to the Wundasmart hub switch."""
-    semaphore = _semaphores.get(wunda_ip)
-    if semaphore is None:
-        semaphore = asyncio.Semaphore(value=1)
-        _semaphores[wunda_ip] = semaphore
-    return semaphore
-
 
 def get_device_id_ranges(hw_version: float):
     id_ranges = DEVICE_ID_RANGES.get(int(math.floor(hw_version)))
@@ -137,10 +127,9 @@ async def get_devices(httpsession: aiohttp.ClientSession, wunda_ip, wunda_user,
     # Query the syncvalues API, which returns a list of all sensor values for all devices. Data is formatted as semicolon-separated k;v pairs
     wunda_url = f"http://{wunda_ip}/syncvalues.cgi"
     try:
-        async with _get_semaphore(wunda_ip), \
-                httpsession.get(wunda_url,
-                                auth=aiohttp.BasicAuth(wunda_user, wunda_pass),
-                                timeout=timeout) as resp:
+        async with httpsession.get(wunda_url,
+                                   auth=aiohttp.BasicAuth(wunda_user, wunda_pass),
+                                   timeout=timeout) as resp:
             status = resp.status
             if status == 200:
                 data = await resp.text()
@@ -169,12 +158,10 @@ async def send_command(session: aiohttp.ClientSession,
     attempts = 0
     while attempts < retries:
         attempts += 1
-
-        async with _get_semaphore(wunda_ip), \
-                session.get(wunda_url,
-                            auth=aiohttp.BasicAuth(wunda_user, wunda_pass), 
-                            params=params,
-                            timeout=timeout) as resp:
+        async with session.get(wunda_url,
+                               auth=aiohttp.BasicAuth(wunda_user, wunda_pass), 
+                               params=params,
+                               timeout=timeout) as resp:
             status = resp.status
             if status == 200:
                 return json.loads(await resp.text())
diff --git a/custom_components/wundasmart/session.py b/custom_components/wundasmart/session.py
index 1c1b8df..a5fa305 100644
--- a/custom_components/wundasmart/session.py
+++ b/custom_components/wundasmart/session.py
@@ -5,6 +5,17 @@
 import weakref
 import socket
 
+# Limit the number of sessions that can be in use at any one time
+_semaphores = {}
+
+def _get_semaphore(wunda_ip):
+    """Return a semaphore object to restrict making concurrent requests to the Wundasmart hub switch."""
+    semaphore = _semaphores.get(wunda_ip)
+    if semaphore is None:
+        semaphore = asyncio.Semaphore(value=1)
+        _semaphores[wunda_ip] = semaphore
+    return semaphore
+
 
 class ResponseHandler(aiohttp.client_proto.ResponseHandler):
     """Patched ResponseHandler that calls socket.shutdown
@@ -49,13 +60,14 @@ def __init__(self, *args, **kwargs):
 
 
 @asynccontextmanager
-async def get_session():
-    connector = TCPConnector(force_close=True, limit=1)
-    try:
-        async with aiohttp.ClientSession(connector=connector) as session:
-            yield session
-    finally:
-        await connector.close()
-        # Zero-sleep to allow underlying connections to close
-        # https://docs.aiohttp.org/en/stable/client_advanced.html#graceful-shutdown
-        await asyncio.sleep(0)
+async def get_session(wunda_ip=None):
+    async with _get_semaphore(wunda_ip):
+        connector = TCPConnector(force_close=True, limit=1)
+        try:
+            async with aiohttp.ClientSession(connector=connector) as session:
+                yield session
+        finally:
+            await connector.close()
+            # Zero-sleep to allow underlying connections to close
+            # https://docs.aiohttp.org/en/stable/client_advanced.html#graceful-shutdown
+            await asyncio.sleep(0)
diff --git a/custom_components/wundasmart/water_heater.py b/custom_components/wundasmart/water_heater.py
index cec29d1..e35ac81 100644
--- a/custom_components/wundasmart/water_heater.py
+++ b/custom_components/wundasmart/water_heater.py
@@ -229,7 +229,7 @@ async def async_set_operation_mode(self, operation_mode: str) -> None:
         if operation_mode:
             if operation_mode in HW_OFF_OPERATIONS:
                 _, duration = _split_operation(operation_mode)
-                async with get_session() as session:
+                async with get_session(self._wunda_ip) as session:
                     await send_command(
                         session,
                         self._wunda_ip,
@@ -242,7 +242,7 @@ async def async_set_operation_mode(self, operation_mode: str) -> None:
                         })
             elif operation_mode in HW_BOOST_OPERATIONS:
                 _, duration = _split_operation(operation_mode)
-                async with get_session() as session:
+                async with get_session(self._wunda_ip) as session:
                     await send_command(
                         session,
                         self._wunda_ip,
@@ -254,7 +254,7 @@ async def async_set_operation_mode(self, operation_mode: str) -> None:
                             "hw_boost_time": duration
                         })
             elif operation_mode == OPERATION_AUTO:
-                async with get_session() as session:
+                async with get_session(self._wunda_ip) as session:
                     await send_command(
                         session,
                         self._wunda_ip,
@@ -278,7 +278,7 @@ async def async_set_operation_mode(self, operation_mode: str) -> None:
     async def async_set_boost(self, duration: timedelta):
         seconds = int((duration.days * 24 * 3600) + math.ceil(duration.seconds))
         if seconds > 0:
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,
@@ -296,7 +296,7 @@ async def async_set_boost(self, duration: timedelta):
     async def async_set_off(self, duration: timedelta):
         seconds = int((duration.days * 24 * 3600) + math.ceil(duration.seconds))
         if seconds > 0:
-            async with get_session() as session:
+            async with get_session(self._wunda_ip) as session:
                 await send_command(
                     session,
                     self._wunda_ip,