diff --git a/LibreHardwareMonitor.Windows.WinUI/MainWindow.cs b/LibreHardwareMonitor.Windows.WinUI/MainWindow.cs
index 58e7521..6153224 100644
--- a/LibreHardwareMonitor.Windows.WinUI/MainWindow.cs
+++ b/LibreHardwareMonitor.Windows.WinUI/MainWindow.cs
@@ -59,9 +59,8 @@ public sealed class MainWindow : Window
     private TextBlock? _measurementTextBlock;
     private readonly List<Grid> _sensorRowGrids = [];
     private readonly double[] _sensorColumnWidths = [DefaultSensorColumnWidth, 120, 120, 120];
-    private PlotWindow? _plotWindow;
+    private readonly SecondaryWindowCoordinator _secondaryWindows;
     private Grid? _sensorHeader;
-    private SensorGadgetWindow? _gadgetWindow;
     private double _stableDeviceColumnWidth = DefaultSensorColumnWidth;
     private bool _deviceColumnWidthSettled;
     private bool _firstLayoutRecorded;
@@ -106,6 +105,7 @@ public sealed class MainWindow : Window
             () => ViewModel.TemperatureUnit));
         _trayIconService.IsMainIconEnabled = ViewModel.MinimizeToTray;
         _dialogService = new DialogService(() => Content.XamlRoot, ViewModel, WindowNative.GetWindowHandle(this));
+        _secondaryWindows = new SecondaryWindowCoordinator(ViewModel, HideShowMainWindow);
 
         Grid root = MeasureStartup("MainWindow.BuildRoot", BuildRoot);
         MeasureStartup("MainWindow.AssignContent", () => Content = root);
@@ -653,7 +653,7 @@ public sealed class MainWindow : Window
 
             UpdateSensorColumnWidths();
             _trayIconService.Update();
-            _gadgetWindow?.UpdateSensors(ViewModel.GetGadgetSensorItems());
+            _secondaryWindows.SyncGadgetSensors();
             DrawPlot();
         }
         catch (Exception ex)
@@ -711,7 +711,7 @@ public sealed class MainWindow : Window
         _timer.Stop();
         _deviceColumnWidthSettleTimer.Stop();
         _trayIconService.Dispose();
-        CloseSecondaryWindows();
+        _secondaryWindows.CloseAll();
         _placementService.Save();
         ViewModel.Dispose();
         _startupTrace?.Dispose();
@@ -742,23 +742,6 @@ public sealed class MainWindow : Window
         Close();
     }
 
-    private void CloseSecondaryWindows()
-    {
-        if (_gadgetWindow != null)
-        {
-            SensorGadgetWindow gadgetWindow = _gadgetWindow;
-            _gadgetWindow = null;
-            gadgetWindow.CloseFromOwner();
-        }
-
-        if (_plotWindow != null)
-        {
-            PlotWindow plotWindow = _plotWindow;
-            _plotWindow = null;
-            plotWindow.CloseFromOwner();
-        }
-    }
-
     private void HideShowMainWindow()
     {
         if (_chromeManager.IsHiddenOrMinimizedOrInvisible)
@@ -792,62 +775,17 @@ public sealed class MainWindow : Window
 
     private void SyncGadgetSensors()
     {
-        _gadgetWindow?.UpdateSensors(ViewModel.GetGadgetSensorItems());
+        _secondaryWindows.SyncGadgetSensors();
     }
 
     private void UpdateGadgetVisibility()
     {
-        if (ViewModel.ShowGadget)
-        {
-            if (_gadgetWindow == null)
-            {
-                _gadgetWindow = new SensorGadgetWindow(ViewModel);
-                _gadgetWindow.HideShowMainWindowRequested += (_, _) => HideShowMainWindow();
-                _gadgetWindow.UserClosed += (_, _) =>
-                {
-                    _gadgetWindow = null;
-                    ViewModel.ShowGadget = false;
-                };
-                SyncGadgetSensors();
-                _gadgetWindow.Activate();
-            }
-
-            return;
-        }
-
-        if (_gadgetWindow != null)
-        {
-            SensorGadgetWindow gadgetWindow = _gadgetWindow;
-            _gadgetWindow = null;
-            gadgetWindow.CloseFromOwner();
-        }
+        _secondaryWindows.UpdateGadgetVisibility();
     }
 
     private void UpdatePlotWindowVisibility()
     {
-        if (ViewModel.IsPlotWindowVisible)
-        {
-            if (_plotWindow == null)
-            {
-                _plotWindow = new PlotWindow(ViewModel.Settings, ViewModel);
-                _plotWindow.ApplyTheme(ViewModel.ThemeMode);
-                _plotWindow.UserClosed += (_, _) =>
-                {
-                    _plotWindow = null;
-                    ViewModel.ShowPlot = false;
-                };
-                _plotWindow.Activate();
-            }
-
-            return;
-        }
-
-        if (_plotWindow != null)
-        {
-            PlotWindow plotWindow = _plotWindow;
-            _plotWindow = null;
-            plotWindow.CloseFromOwner();
-        }
+        _secondaryWindows.UpdatePlotWindowVisibility();
     }
 
     private void RebuildSensorTree()
@@ -1102,7 +1040,7 @@ public sealed class MainWindow : Window
     {
         ViewModel.ResetPlot();
         _plotView.ResetZoom();
-        _plotWindow?.RedrawPlot();
+        _secondaryWindows.RedrawPlot();
     }
 
     private void DrawPlot()
@@ -1112,7 +1050,7 @@ public sealed class MainWindow : Window
         else
             _plotView.Redraw();
 
-        _plotWindow?.RedrawPlot();
+        _secondaryWindows.RedrawPlot();
     }
 
     private void UpdatePlotLayout()
@@ -1148,7 +1086,7 @@ public sealed class MainWindow : Window
         };
 
         _plotView.ApplyTheme(ViewModel.ThemeMode);
-        _plotWindow?.ApplyTheme(ViewModel.ThemeMode);
+        _secondaryWindows.ApplyTheme(ViewModel.ThemeMode);
     }
 
     private void UpdateSensorColumnWidths()
diff --git a/LibreHardwareMonitor.Windows.WinUI/Services/SecondaryWindowCoordinator.cs b/LibreHardwareMonitor.Windows.WinUI/Services/SecondaryWindowCoordinator.cs
new file mode 100644
index 0000000..5cab229
--- /dev/null
+++ b/LibreHardwareMonitor.Windows.WinUI/Services/SecondaryWindowCoordinator.cs
@@ -0,0 +1,109 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+// Copyright (C) LibreHardwareMonitor and Contributors.
+
+using System;
+using LibreHardwareMonitor.Windows.WinUI.ViewModels;
+
+namespace LibreHardwareMonitor.Windows.WinUI.Services;
+
+internal sealed class SecondaryWindowCoordinator
+{
+    private readonly MainWindowViewModel _viewModel;
+    private readonly Action _hideShowMainWindowRequested;
+    private PlotWindow? _plotWindow;
+    private SensorGadgetWindow? _gadgetWindow;
+
+    public SecondaryWindowCoordinator(MainWindowViewModel viewModel, Action hideShowMainWindowRequested)
+    {
+        _viewModel = viewModel ?? throw new ArgumentNullException(nameof(viewModel));
+        _hideShowMainWindowRequested = hideShowMainWindowRequested ?? throw new ArgumentNullException(nameof(hideShowMainWindowRequested));
+    }
+
+    public void UpdateGadgetVisibility()
+    {
+        if (_viewModel.ShowGadget)
+        {
+            if (_gadgetWindow == null)
+            {
+                _gadgetWindow = new SensorGadgetWindow(_viewModel);
+                _gadgetWindow.HideShowMainWindowRequested += (_, _) => _hideShowMainWindowRequested();
+                _gadgetWindow.UserClosed += (_, _) =>
+                {
+                    _gadgetWindow = null;
+                    _viewModel.ShowGadget = false;
+                };
+                SyncGadgetSensors();
+                _gadgetWindow.Activate();
+            }
+
+            return;
+        }
+
+        if (_gadgetWindow != null)
+        {
+            SensorGadgetWindow gadgetWindow = _gadgetWindow;
+            _gadgetWindow = null;
+            gadgetWindow.CloseFromOwner();
+        }
+    }
+
+    public void UpdatePlotWindowVisibility()
+    {
+        if (_viewModel.IsPlotWindowVisible)
+        {
+            if (_plotWindow == null)
+            {
+                _plotWindow = new PlotWindow(_viewModel.Settings, _viewModel);
+                _plotWindow.ApplyTheme(_viewModel.ThemeMode);
+                _plotWindow.UserClosed += (_, _) =>
+                {
+                    _plotWindow = null;
+                    _viewModel.ShowPlot = false;
+                };
+                _plotWindow.Activate();
+            }
+
+            return;
+        }
+
+        if (_plotWindow != null)
+        {
+            PlotWindow plotWindow = _plotWindow;
+            _plotWindow = null;
+            plotWindow.CloseFromOwner();
+        }
+    }
+
+    public void SyncGadgetSensors()
+    {
+        _gadgetWindow?.UpdateSensors(_viewModel.GetGadgetSensorItems());
+    }
+
+    public void ApplyTheme(AppThemeMode themeMode)
+    {
+        _plotWindow?.ApplyTheme(themeMode);
+    }
+
+    public void RedrawPlot()
+    {
+        _plotWindow?.RedrawPlot();
+    }
+
+    public void CloseAll()
+    {
+        if (_gadgetWindow != null)
+        {
+            SensorGadgetWindow gadgetWindow = _gadgetWindow;
+            _gadgetWindow = null;
+            gadgetWindow.CloseFromOwner();
+        }
+
+        if (_plotWindow != null)
+        {
+            PlotWindow plotWindow = _plotWindow;
+            _plotWindow = null;
+            plotWindow.CloseFromOwner();
+        }
+    }
+}