diff --git a/idm/idm.cpp b/idm/idm.cpp
index a948bfd..3c5f7ee 100644
--- a/idm/idm.cpp
+++ b/idm/idm.cpp
@@ -43,6 +43,8 @@ Idm::Idm(const QHostAddress &address, QObject *parent) :
         m_modbusMaster->connectDevice();
 
         connect(m_modbusMaster, &ModbusTCPMaster::receivedHoldingRegister, this, &Idm::onReceivedHoldingRegister);
+        connect(m_modbusMaster, &ModbusTCPMaster::readRequestError, this, &Idm::onModbusError);
+        connect(m_modbusMaster, &ModbusTCPMaster::writeRequestError, this, &Idm::onModbusError);
     }
 }
 
@@ -90,6 +92,12 @@ void Idm::onReceivedHoldingRegister(int slaveAddress, int modbusRegister, const
         if (value.length() == 1) {
             m_info->m_mode = heatPumpOperationModeToString((Idm::IdmHeatPumpMode)value[RegisterList::HeatPumpOperatingMode-modbusRegister]);
         }
+        m_modbusMaster->readHoldingRegister(Idm::ModbusUnitID, Idm::HumiditySensor, 2);
+        break;
+    case Idm::HumiditySensor:
+        if (value.length() == 2) {
+            m_info->m_humidity = ModbusHelpers::convertRegisterToFloat(&value[RegisterList::HumiditySensor - modbusRegister]);
+        }
         m_modbusMaster->readHoldingRegister(Idm::ModbusUnitID, Idm::RoomTemperatureHKA, 2);
         break;
     case Idm::RoomTemperatureHKA:
@@ -97,11 +105,25 @@ void Idm::onReceivedHoldingRegister(int slaveAddress, int modbusRegister, const
             m_info->m_roomTemperature = ModbusHelpers::convertRegisterToFloat(&value[RegisterList::ExternalOutsideTemperature - modbusRegister]);
         }
 
+        /* Everything read without an error
+         * -> set connected to true */
+        m_info->m_connected = true;
         emit statusUpdated(m_info);
         break;
     }
 }
 
+void Idm::onModbusError()
+{
+    if (m_info == nullptr) {
+        m_info = new IdmInfo;
+    }
+
+    m_info->m_connected = false;
+
+    emit statusUpdated(m_info);
+}
+
 void Idm::onRequestStatus()
 {
     m_info = new IdmInfo;
diff --git a/idm/idm.h b/idm/idm.h
index 152acc5..4832eb0 100644
--- a/idm/idm.h
+++ b/idm/idm.h
@@ -103,7 +103,7 @@ private:
         HeatPumpOperatingMode           = 1090, // Betriebsart Wärmepumpe
         SummationFaultHeatPump          = 1099, // Summenstörung Wärepumpe
         RoomTemperatureHKA              = 1364, // Heizkreis A Raumtemperature (B61)
-        Humiditysensor                  = 1392, // Feuchtesensor
+        HumiditySensor                  = 1392, // Feuchtesensor
         RoomTemperatureTargetHeatingHKA = 1401, // Raumsolltemperatur Heizen Normal HK A
         ExternalOutsideTemperature      = 1690, // Externe Außentemperatur
         ExternalHumidity                = 1692, // Externe Feuchte
@@ -155,6 +155,7 @@ signals:
     void statusUpdated(IdmInfo *info);
 
 public slots:
+    void onModbusError();
     void onRequestStatus();
     void onReceivedHoldingRegister(int slaveAddress, int modbusRegister, const QVector<quint16> &value);
 };
diff --git a/idm/idminfo.h b/idm/idminfo.h
index e43438f..7b51380 100644
--- a/idm/idminfo.h
+++ b/idm/idminfo.h
@@ -38,7 +38,10 @@
  *  and passed to the nymea framework within this plugin.
  */
 struct IdmInfo {
+    /** Set to true, if register values can be read,
+     *  false in case of communication problems */
     bool    m_connected;
+
     bool    m_power;
 
     /** RegisterList::OutsideTemperature */
@@ -56,6 +59,9 @@ struct IdmInfo {
     /** RegisterList::TargetHotWaterTemperature */
     double  m_targetWaterTemperature;
 
+    /** RegisterList::HumiditySensor */
+    double  m_humidity;
+
     /** RegisterList::OperationModeSystem */
     QString m_mode;
 
diff --git a/idm/integrationpluginidm.json b/idm/integrationpluginidm.json
index edc139d..69a4715 100644
--- a/idm/integrationpluginidm.json
+++ b/idm/integrationpluginidm.json
@@ -13,7 +13,7 @@
                     "displayName": "Navigator 2.0",
                     "id": "1c95ac91-4eca-4cbf-b0f4-d60d35d069ed",
                     "createMethods": ["User","Discovery"],
-                    "interfaces": ["heating", "temperaturesensor", "connectable"],
+                    "interfaces": ["thermostat", "temperaturesensor", "humiditysensor", "connectable"],
                     "paramTypes": [
                         {
                             "id": "05714e5c-d66a-4095-bbff-a0eb96fb035b",
@@ -69,6 +69,15 @@
                             "unit": "DegreeCelsius",
                             "defaultValue": 0
                         },
+                        {
+                            "id": "109b4189-491a-4498-8470-b52b1b434c71",
+                            "name": "humidity",
+                            "displayName": "Humidity",
+                            "displayNameEvent": "Humidity changed",
+                            "type": "double",
+                            "minValue": 0,
+                            "maxValue": 100
+                        },
                         {
                             "id": "efae7493-68c3-4cb9-853c-81011bdf09ca",
                             "name": "targetTemperature",
diff --git a/modbus/modbustcpmaster.cpp b/modbus/modbustcpmaster.cpp
index 88eacb7..3220842 100644
--- a/modbus/modbustcpmaster.cpp
+++ b/modbus/modbustcpmaster.cpp
@@ -305,21 +305,22 @@ QUuid ModbusTCPMaster::readHoldingRegister(uint slaveAddress, uint registerAddre
             connect(reply, &QModbusReply::finished, this, [reply, requestId, this] {
 
                 if (reply->error() == QModbusDevice::NoError) {
-                    writeRequestExecuted(requestId, true);
+                    emit writeRequestExecuted(requestId, true);
                     const QModbusDataUnit unit = reply->result();
                     uint modbusAddress = unit.startAddress();
                     emit receivedHoldingRegister(reply->serverAddress(), modbusAddress, unit.values());
 
                 } else {
-                    writeRequestExecuted(requestId, false);
+                    emit writeRequestExecuted(requestId, false);
                     qCWarning(dcModbusTCP()) << "Read response error:" << reply->error();
+                    emit readRequestError(requestId, reply->errorString());
                 }
                 reply->deleteLater();
             });
             connect(reply, &QModbusReply::errorOccurred, this, [reply, requestId, this] (QModbusDevice::Error error){
 
-                qCWarning(dcModbusTCP()) << "Modbus replay error:" << error;
-                emit writeRequestError(requestId, reply->errorString());
+                qCWarning(dcModbusTCP()) << "Modbus reply error:" << error;
+                emit readRequestError(requestId, reply->errorString());
                 reply->finished(); // To make sure it will be deleted
             });
             QTimer::singleShot(2000, reply, &QModbusReply::deleteLater);
@@ -340,7 +341,7 @@ QUuid ModbusTCPMaster::writeCoil(uint slaveAddress, uint registerAddress, bool v
 }
 
 QUuid ModbusTCPMaster::writeCoils(uint slaveAddress, uint registerAddress, const QVector<quint16> &values)
-    {
+{
     if (!m_modbusTcpClient) {
         return "";
     }
@@ -355,14 +356,14 @@ QUuid ModbusTCPMaster::writeCoils(uint slaveAddress, uint registerAddress, const
             connect(reply, &QModbusReply::finished, this, [reply, requestId, this] () {
 
                 if (reply->error() == QModbusDevice::NoError) {
-                    writeRequestExecuted(requestId, true);
+                    emit writeRequestExecuted(requestId, true);
                     const QModbusDataUnit unit = reply->result();
                     uint modbusAddress = unit.startAddress();
                     emit receivedCoil(reply->serverAddress(), modbusAddress, unit.values());
 
                 } else {
-                    writeRequestExecuted(requestId, false);
-                    qCWarning(dcModbusTCP()) << "Read response error:" << reply->error();
+                    emit writeRequestExecuted(requestId, false);
+                    qCWarning(dcModbusTCP()) << "Write response error:" << reply->error();
                 }
                 reply->deleteLater();
             });
diff --git a/modbus/modbustcpmaster.h b/modbus/modbustcpmaster.h
index 86aa28c..bede700 100644
--- a/modbus/modbustcpmaster.h
+++ b/modbus/modbustcpmaster.h
@@ -82,6 +82,7 @@ signals:
 
     void writeRequestExecuted(const QUuid &requestId, bool success);
     void writeRequestError(const QUuid &requestId, const QString &error);
+    void readRequestError(const QUuid &requestId, const QString &error);
 
     void receivedCoil(uint slaveAddress, uint modbusRegister, const QVector<quint16> &values);
     void receivedDiscreteInput(uint slaveAddress, uint modbusRegister, const QVector<quint16> &values);