diff --git a/Environment/Service/DeviceCheckService.cs b/Environment/Service/DeviceCheckService.cs
new file mode 100644
index 0000000..6088391
--- /dev/null
+++ b/Environment/Service/DeviceCheckService.cs
@@ -0,0 +1,77 @@
+using ChrisKaczor.HomeMonitor.Environment.Service.Data;
+using RestSharp;
+
+namespace ChrisKaczor.HomeMonitor.Environment.Service;
+
+public class DeviceCheckService(Database _database, IConfiguration _configuration) : IHostedService
+{
+    private Timer? _timer;
+    private TimeSpan _warningInterval;
+
+    private readonly string _botToken = _configuration["Telegram:BotToken"]!;
+    private readonly string _chatId = _configuration["Telegram:ChatId"]!;
+    private readonly RestClient _restClient = new();
+
+    public Task StartAsync(CancellationToken cancellationToken)
+    {
+        WriteLog("DeviceCheckService started");
+
+        _warningInterval = TimeSpan.Parse(_configuration["Environment:DeviceWarningInterval"]!);
+
+        var checkInterval = TimeSpan.Parse(_configuration["Environment:DeviceCheckInterval"]!);
+
+        _timer = new Timer((state) => DoWork().Wait(), null, TimeSpan.Zero, checkInterval);
+
+        return Task.CompletedTask;
+    }
+
+    private async Task DoWork()
+    {
+        WriteLog("Checking devices started");
+
+        var devices = await _database.GetDevicesAsync();
+
+        foreach (var device in devices)
+        {
+            WriteLog($"Checking device: {device.Name}");
+
+            var message = string.Empty;
+
+            WriteLog($"Device {device.Name} last updated: {(device.LastUpdated == null ? "never" : device.LastUpdated.ToString())}");
+
+            if (device.LastUpdated == null)
+            {
+                message = $"Device has never reported: {device.Name}";
+            }
+            else if (DateTime.UtcNow - device.LastUpdated > _warningInterval)
+            {
+                message = $"Device has not reported recently: {device.Name}";
+            }
+
+            if (message.Length > 0)
+            {
+                var encodedMessage = Uri.EscapeDataString(message);
+
+                var restRequest = new RestRequest($"https://api.telegram.org/bot{_botToken}/sendMessage?chat_id={_chatId}&text={encodedMessage}");
+
+                await _restClient.GetAsync(restRequest);
+            }
+        }
+
+        WriteLog("Checking devices finished");
+    }
+
+    public Task StopAsync(CancellationToken cancellationToken)
+    {
+        WriteLog("DeviceCheckService stopped");
+
+        _timer?.Change(Timeout.Infinite, 0);
+
+        return Task.CompletedTask;
+    }
+
+    private static void WriteLog(string message)
+    {
+        Console.WriteLine(message);
+    }
+}
\ No newline at end of file
diff --git a/Environment/Service/Program.cs b/Environment/Service/Program.cs
index a85f74a..e7ac160 100644
--- a/Environment/Service/Program.cs
+++ b/Environment/Service/Program.cs
@@ -20,6 +20,7 @@ public static class Program
 
         builder.Services.AddTransient<Database>();
         builder.Services.AddHostedService<MessageHandler>();
+        builder.Services.AddHostedService<DeviceCheckService>();
 
         // -- -- 
 
diff --git a/Environment/Service/Service.csproj b/Environment/Service/Service.csproj
index 75e4955..8c63f45 100644
--- a/Environment/Service/Service.csproj
+++ b/Environment/Service/Service.csproj
@@ -40,6 +40,7 @@
     <PackageReference Include="JetBrains.Annotations" Version="2023.3.0" />
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.1" />
     <PackageReference Include="MQTTnet.AspNetCore" Version="4.3.3.952" />
+    <PackageReference Include="RestSharp" Version="111.1.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/Environment/Service/appsettings.Development.json b/Environment/Service/appsettings.Development.json
index 1dc206b..1af1a15 100644
--- a/Environment/Service/appsettings.Development.json
+++ b/Environment/Service/appsettings.Development.json
@@ -1,25 +1,31 @@
 {
-    "Logging": {
-        "LogLevel": {
-            "Default": "Information",
-            "Microsoft.AspNetCore": "Warning"
-        }
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "Mqtt": {
+    "Server": "172.23.10.3"
+  },
+  "Environment": {
+    "Database": {
+      "Host": "localhost",
+      "User": "postgres",
+      "Password": "postgres",
+      "Port": 5432,
+      "Name": "Environment",
+      "TrustServerCertificate": true
     },
-    "Mqtt": {
-        "Server": "172.23.10.3"
+    "Hub": {
+      "Url": "http://localhost:8080/environment"
     },
-    "Environment": {
-        "Database": {
-            "Host": "localhost",
-            "User": "postgres",
-            "Password": "postgres",
-            "Port": 5432,
-            "Name": "Environment",
-            "TrustServerCertificate": true
-        },
-        "Hub": {
-            "Url": "http://localhost:8080/environment"
-        }
-    },
-    "AuthorizationToken": "test-token"
+    "DeviceCheckInterval": "00:00:30",
+    "DeviceWarningInterval": "00:00:10"
+  },
+  "AuthorizationToken": "test-token",
+  "Telegram": {
+    "BotToken": "",
+    "ChatId": ""
+  }
 }
diff --git a/Environment/Service/appsettings.json b/Environment/Service/appsettings.json
index be22a58..778dae6 100644
--- a/Environment/Service/appsettings.json
+++ b/Environment/Service/appsettings.json
@@ -21,7 +21,9 @@
         },
         "Hub": {
             "Url": "http://hub-server/environment"
-        }
+        },
+        "DeviceCheckInterval": "01:00:00",
+        "DeviceWarningInterval": "01:00:00"
     },
     "Telemetry": {
         "Endpoint": "http://signoz-otel-collector.platform:4317/"