diff --git a/platformio.ini b/platformio.ini
index 06a458b..fc07555 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -15,7 +15,7 @@
     platform = espressif32
     framework = arduino
     lib_deps = 
-        https://github.com/tzapu/WiFiManager.git
+        https://github.com/PBRunot/WiFiManager.git#0404abde0d9d2da5c09be7d0cc669b1188bb1c81
         https://github.com/me-no-dev/ESPAsyncWebServer.git
         https://github.com/eModbus/eModbus.git
         https://github.com/bblanchon/ArduinoJson.git
diff --git a/src/localmodbus.cpp b/src/localmodbus.cpp
index 5932781..ead2ff1 100644
--- a/src/localmodbus.cpp
+++ b/src/localmodbus.cpp
@@ -117,6 +117,7 @@ ModbusMessage FC02(ModbusMessage request) {
 }
 
 // FC03: worker do serve Modbus function code 0x03 (READ_HOLD_REGISTER)
+// Gets the current temperature (from address 0x00 with a length of 4 Bytes)
 ModbusMessage FC03(ModbusMessage request) {
     uint16_t address;           // requested register address
     uint16_t words;             // requested number of registers
@@ -141,6 +142,32 @@ ModbusMessage FC03(ModbusMessage request) {
     return response;
 }
 
+// FC04: worker do serve Modbus function code 0x04 (READ_INPUT_REGISTER)
+// Gets the current temperature (from address 0x00 with a length of 4 Bytes)
+ModbusMessage FC04(ModbusMessage request) {
+    uint16_t address;           // requested register address
+    uint16_t words;             // requested number of registers
+    ModbusMessage response;     // response message to be sent back
+
+    LOG_D("Worker for FC04\n");
+
+    // get request values
+    request.get(2, address);
+    request.get(4, words);
+
+    // return current temperature
+    if (address == 0 && words == 2) {
+        // Looks okay. Set up message with serverID, FC and length of data
+        response.add(request.getServerID(), request.getFunctionCode(), (uint8_t)(words * 2));
+        // add current temperature to response
+        response.add(temperatureRead());
+    } else {
+        // Set up error response.
+        response.setError(request.getServerID(), request.getFunctionCode(), ILLEGAL_DATA_ADDRESS);
+    }
+    return response;
+}
+
 // FC05: worker do serve Modbus function code 0x05 (WRITE_COIL)
 ModbusMessage FC05(ModbusMessage request) {
     uint16_t address;           // requested coil
@@ -255,14 +282,14 @@ void setupLocalModbus(uint8_t serverID, ModbusClientRTU *rtu, ModbusBridgeWiFi *
     _bridge = bridge;
     _config = config;
     _serverID = serverID;
-    bridge->registerWorker(serverID, READ_HOLD_REGISTER, &FC03);
+    //bridge->registerWorker(serverID, READ_HOLD_REGISTER, &FC03);
+    bridge->registerWorker(serverID, READ_INPUT_REGISTER, &FC04);
     bridge->registerWorker(serverID, DIAGNOSTICS_SERIAL, &FC08);
 }
 
 void enableCoilWorkers() {
     _bridge->registerWorker(_serverID, READ_COIL, &FC01);
     _bridge->registerWorker(_serverID, WRITE_COIL, &FC05);
-    // _bridge->registerWorker(_serverID, WRITE_MULT_COILS, &FC0F); 
 }
 
 void enableInputWorkers() {