diff --git a/cura/PrinterOutput/NetworkedPrinterOutputDevice.py b/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
index bbeb87d5e3..0e33a71249 100644
--- a/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
+++ b/cura/PrinterOutput/NetworkedPrinterOutputDevice.py
@@ -310,11 +310,11 @@ class NetworkedPrinterOutputDevice(PrinterOutputDevice):
     def _createNetworkManager(self) -> None:
         Logger.log("d", "Creating network manager")
         if self._manager:
-            self._manager.finished.disconnect(self.__handleOnFinished)
+            self._manager.finished.disconnect(self._handleOnFinished)
             self._manager.authenticationRequired.disconnect(self._onAuthenticationRequired)
 
         self._manager = QNetworkAccessManager()
-        self._manager.finished.connect(self.__handleOnFinished)
+        self._manager.finished.connect(self._handleOnFinished)
         self._last_manager_create_time = time()
         self._manager.authenticationRequired.connect(self._onAuthenticationRequired)
 
@@ -325,7 +325,7 @@ class NetworkedPrinterOutputDevice(PrinterOutputDevice):
         if on_finished is not None:
             self._onFinishedCallbacks[reply.url().toString() + str(reply.operation())] = on_finished
 
-    def __handleOnFinished(self, reply: QNetworkReply) -> None:
+    def _handleOnFinished(self, reply: QNetworkReply) -> None:
         # Due to garbage collection, we need to cache certain bits of post operations.
         # As we don't want to keep them around forever, delete them if we get a reply.
         if reply.operation() == QNetworkAccessManager.PostOperation:
diff --git a/tests/PrinterOutput/TestNetworkedPrinterOutputDevice.py b/tests/PrinterOutput/TestNetworkedPrinterOutputDevice.py
new file mode 100644
index 0000000000..b3f7277051
--- /dev/null
+++ b/tests/PrinterOutput/TestNetworkedPrinterOutputDevice.py
@@ -0,0 +1,133 @@
+import time
+from unittest.mock import MagicMock
+
+from PyQt5.QtNetwork import QNetworkAccessManager
+from PyQt5.QtCore import QUrl
+from cura.PrinterOutput.NetworkedPrinterOutputDevice import NetworkedPrinterOutputDevice, AuthState
+from cura.PrinterOutputDevice import ConnectionState
+
+
+def test_properties():
+    properties = { b"firmware_version": b"12", b"printer_type": b"BHDHAHHADAD", b"address": b"ZOMG", b"name": b":(", b"testProp": b"zomg"}
+
+    output_device = NetworkedPrinterOutputDevice(device_id = "test", address = "127.0.0.1", properties = properties)
+    assert output_device.address == "ZOMG"
+    assert output_device.firmwareVersion == "12"
+    assert output_device.printerType == "BHDHAHHADAD"
+    assert output_device.ipAddress == "127.0.0.1"
+    assert output_device.name == ":("
+    assert output_device.key == "test"
+    assert output_device.getProperties() == properties
+
+    assert output_device.getProperty("testProp") == "zomg"
+    assert output_device.getProperty("whateverr") == ""
+
+
+def test_authenticationState():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+
+    output_device.setAuthenticationState(AuthState.Authenticated)
+
+    assert output_device.authenticationState == AuthState.Authenticated
+
+
+def test_post():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+    mocked_network_manager = MagicMock()
+    output_device._manager = mocked_network_manager
+
+    # Create a fake reply (we cant use a QReply, since those are abstract C++)
+    reply = MagicMock()
+    reply.operation = MagicMock(return_value=QNetworkAccessManager.PostOperation)
+    reply.url = MagicMock(return_value=QUrl("127.0.0.1"))
+    mocked_network_manager.post = MagicMock(return_value = reply)
+
+    mocked_callback_handler = MagicMock()
+    output_device.post("whatever", "omgzomg", on_finished = mocked_callback_handler.onFinished)
+
+    # So we now fake that the request was sucesful.
+    output_device._handleOnFinished(reply)
+
+    # We expect to get a callback regarding this.
+    mocked_callback_handler.onFinished.assert_called_once_with(reply)
+
+
+def test_get():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+    mocked_network_manager = MagicMock()
+    output_device._manager = mocked_network_manager
+
+    # Create a fake reply (we cant use a QReply, since those are abstract C++)
+    reply = MagicMock()
+    reply.operation = MagicMock(return_value=QNetworkAccessManager.PostOperation)
+    reply.url = MagicMock(return_value=QUrl("127.0.0.1"))
+    mocked_network_manager.get = MagicMock(return_value=reply)
+
+    mocked_callback_handler = MagicMock()
+    output_device.get("whatever", on_finished=mocked_callback_handler.onFinished)
+
+    # So we now fake that the request was sucesful.
+    output_device._handleOnFinished(reply)
+
+    # We expect to get a callback regarding this.
+    mocked_callback_handler.onFinished.assert_called_once_with(reply)
+
+
+def test_delete():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+    mocked_network_manager = MagicMock()
+    output_device._manager = mocked_network_manager
+
+    # Create a fake reply (we cant use a QReply, since those are abstract C++)
+    reply = MagicMock()
+    reply.operation = MagicMock(return_value=QNetworkAccessManager.PostOperation)
+    reply.url = MagicMock(return_value=QUrl("127.0.0.1"))
+    mocked_network_manager.deleteResource = MagicMock(return_value=reply)
+
+    mocked_callback_handler = MagicMock()
+    output_device.delete("whatever", on_finished=mocked_callback_handler.onFinished)
+
+    # So we now fake that the request was sucesful.
+    output_device._handleOnFinished(reply)
+
+    # We expect to get a callback regarding this.
+    mocked_callback_handler.onFinished.assert_called_once_with(reply)
+
+
+def test_put():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+    mocked_network_manager = MagicMock()
+    output_device._manager = mocked_network_manager
+
+    # Create a fake reply (we cant use a QReply, since those are abstract C++)
+    reply = MagicMock()
+    reply.operation = MagicMock(return_value=QNetworkAccessManager.PostOperation)
+    reply.url = MagicMock(return_value=QUrl("127.0.0.1"))
+    mocked_network_manager.put = MagicMock(return_value = reply)
+
+    mocked_callback_handler = MagicMock()
+    output_device.put("whatever", "omgzomg", on_finished = mocked_callback_handler.onFinished)
+
+    # So we now fake that the request was sucesful.
+    output_device._handleOnFinished(reply)
+
+    # We expect to get a callback regarding this.
+    mocked_callback_handler.onFinished.assert_called_once_with(reply)
+
+
+def test_timeout():
+    output_device = NetworkedPrinterOutputDevice(device_id="test", address="127.0.0.1", properties={})
+    output_device.setConnectionState(ConnectionState.Connected)
+
+    assert output_device.connectionState == ConnectionState.Connected
+    output_device._update()
+    # Pretend we didn't get any response for 15 seconds
+    output_device._last_response_time = time.time() - 15
+    # But we did recently ask for a response!
+    output_device._last_request_time = time.time() - 5
+    output_device._update()
+
+    # The connection should now be closed, since it went into timeout.
+    assert output_device.connectionState == ConnectionState.Closed
+
+