diff --git a/lib/screens/home_edit_screen.dart b/lib/screens/home_edit_screen.dart
index 32cdd91..9ff6f61 100644
--- a/lib/screens/home_edit_screen.dart
+++ b/lib/screens/home_edit_screen.dart
@@ -25,6 +25,7 @@ class _HomeEditScreenState extends ConsumerState<HomeEditScreen> {
   final _lonCtrl = TextEditingController();
   bool _saving = false;
   bool _loadingApiKey = false;
+  bool _hasStoredApiKey = false;
   String _originalApiKey = '';
 
   bool get _isEdit => widget.home != null;
@@ -59,11 +60,11 @@ class _HomeEditScreenState extends ConsumerState<HomeEditScreen> {
       final apiKey = await ref
           .read(settingsServiceProvider)
           .getHomeApiKey(widget.home!.id);
-      _originalApiKey = apiKey ?? '';
+      _originalApiKey = apiKey?.trim() ?? '';
+      _hasStoredApiKey = _originalApiKey.isNotEmpty;
       if (!mounted) {
         return;
       }
-      _keyCtrl.text = _originalApiKey;
     } finally {
       if (mounted) {
         setState(() => _loadingApiKey = false);
@@ -144,14 +145,24 @@ class _HomeEditScreenState extends ConsumerState<HomeEditScreen> {
                 controller: _keyCtrl,
                 decoration: InputDecoration(
                   labelText: 'API Key',
+                  hintText: _hasStoredApiKey
+                      ? 'Оставьте пустым, чтобы сохранить текущий ключ'
+                      : null,
                   helperText: _loadingApiKey
                       ? 'Загружаем сохранённый ключ...'
-                      : 'Ключ проверяется только при изменении подключения',
+                      : _hasStoredApiKey
+                      ? 'Сохранённый ключ хранится отдельно и не показывается в поле'
+                      : 'Ключ хранится отдельно в защищённом хранилище',
                   prefixIcon: const Icon(Icons.key),
                 ),
                 obscureText: true,
-                validator: (value) =>
-                    (value?.trim().isEmpty ?? true) ? 'Укажите API key' : null,
+                validator: (value) {
+                  final enteredKey = value?.trim() ?? '';
+                  if (enteredKey.isNotEmpty || _hasStoredApiKey) {
+                    return null;
+                  }
+                  return 'Укажите API key';
+                },
               ),
               const SizedBox(height: 24),
               const Text(
@@ -285,7 +296,8 @@ class _HomeEditScreenState extends ConsumerState<HomeEditScreen> {
 
     final name = _nameCtrl.text.trim();
     final rawUrl = _urlCtrl.text.trim();
-    final key = _keyCtrl.text.trim();
+    final enteredKey = _keyCtrl.text.trim();
+    final key = enteredKey.isNotEmpty ? enteredKey : _originalApiKey;
     final latText = _latCtrl.text.trim();
     final lonText = _lonCtrl.text.trim();
 
@@ -370,7 +382,7 @@ class _HomeEditScreenState extends ConsumerState<HomeEditScreen> {
       if (_isEdit) {
         await ref
             .read(homesProvider.notifier)
-            .update(home, apiKey: credentialsChanged ? key : null);
+            .update(home, apiKey: enteredKey.isNotEmpty ? key : null);
       } else {
         await ref.read(homesProvider.notifier).add(home, apiKey: key);
       }
diff --git a/test/forms_widget_test.dart b/test/forms_widget_test.dart
index 1840257..d56739b 100644
--- a/test/forms_widget_test.dart
+++ b/test/forms_widget_test.dart
@@ -82,25 +82,25 @@ void main() {
     expect(api.createdGroupMacs, ['AA:BB']);
   });
 
-  testWidgets('group edit screen shows backend rescan summary', (
-    tester,
-  ) async {
-    final api = FakeIgnisApi(
-      devicesData: {
-        'devices': [
-          {'mac': 'AA:BB', 'name': 'Лампа 1'},
-        ],
-      },
-      groupsData: <Object>[],
-    )..rescanNetworkData = {
-      'status': 'ok',
-      'found': 3,
-      'added': 1,
-      'updated': 2,
-      'removed_offline': 1,
-      'pending_removal': 0,
-      'online': 3,
-    };
+  testWidgets('group edit screen shows backend rescan summary', (tester) async {
+    final api =
+        FakeIgnisApi(
+            devicesData: {
+              'devices': [
+                {'mac': 'AA:BB', 'name': 'Лампа 1'},
+              ],
+            },
+            groupsData: <Object>[],
+          )
+          ..rescanNetworkData = {
+            'status': 'ok',
+            'found': 3,
+            'added': 1,
+            'updated': 2,
+            'removed_offline': 1,
+            'pending_removal': 0,
+            'online': 3,
+          };
 
     await pumpTestApp(tester, child: const GroupEditScreen(), api: api);
     await tester.pumpAndSettle();
@@ -109,7 +109,9 @@ void main() {
     await tester.pumpAndSettle();
 
     expect(
-      find.text('Сканирование завершено: найдено 3, новых 1, обновлено 2, убрано 1'),
+      find.text(
+        'Сканирование завершено: найдено 3, новых 1, обновлено 2, убрано 1',
+      ),
       findsOneWidget,
     );
     expect(api.rescanCalls, 1);
@@ -228,4 +230,57 @@ void main() {
     );
     expect(savedApiKey, 'secret-key');
   });
+
+  testWidgets('home edit screen keeps stored api key hidden on edit', (
+    tester,
+  ) async {
+    SharedPreferences.setMockInitialValues({});
+    final settingsService = SettingsService(
+      credentialsStorage: InMemoryCredentialsStorage(),
+    );
+    final existingHome = HomeConfig(
+      id: 'home-1',
+      name: 'Квартира',
+      url: 'https://ignis.akokos.ru',
+    );
+    await settingsService.upsertHome(existingHome, apiKey: 'stored-secret');
+
+    final api = FakeIgnisApi(authData: {'is_admin': true, 'name': 'owner'});
+
+    await pumpTestApp(
+      tester,
+      api: api,
+      settingsService: settingsService,
+      child: HomeEditScreen(home: existingHome),
+    );
+    await tester.pumpAndSettle();
+
+    final keyField = tester.widget<EditableText>(
+      find.byWidgetPredicate(
+        (widget) => widget is EditableText && widget.obscureText,
+      ),
+    );
+    expect(keyField.controller.text, isEmpty);
+    expect(
+      find.text('Сохранённый ключ хранится отдельно и не показывается в поле'),
+      findsOneWidget,
+    );
+
+    await tester.enterText(
+      find.widgetWithText(TextFormField, 'Адрес сервера'),
+      'ignis.example.com',
+    );
+    await tester.pump();
+
+    await tester.tap(find.widgetWithText(ElevatedButton, 'СОХРАНИТЬ'));
+    await tester.pumpAndSettle();
+
+    expect(api.validateCredentialsCalls, 1);
+    expect(api.validatedBaseUrl, 'https://ignis.example.com');
+    expect(api.validatedApiKey, 'stored-secret');
+    expect(
+      await settingsService.getHomeApiKey(existingHome.id),
+      'stored-secret',
+    );
+  });
 }
diff --git a/test/test_support.dart b/test/test_support.dart
index a61f29d..7966984 100644
--- a/test/test_support.dart
+++ b/test/test_support.dart
@@ -73,6 +73,9 @@ class FakeIgnisApi extends IgnisApi {
   String? deletedGroupId;
   Map<String, dynamic>? scheduledOnceParams;
   Map<String, dynamic>? scheduledCronParams;
+  String? validatedBaseUrl;
+  String? validatedApiKey;
+  int validateCredentialsCalls = 0;
   int rescanCalls = 0;
 
   FakeIgnisApi({
@@ -99,6 +102,9 @@ class FakeIgnisApi extends IgnisApi {
 
   @override
   Future<void> validateCredentials(String baseUrl, String apiKey) async {
+    validateCredentialsCalls += 1;
+    validatedBaseUrl = baseUrl;
+    validatedApiKey = apiKey;
     final error = authError;
     if (error != null) throw error;
   }