diff --git a/code/espurna/sensors/BMX280Sensor.h b/code/espurna/sensors/BMX280Sensor.h
index 4e6342e3..93677436 100644
--- a/code/espurna/sensors/BMX280Sensor.h
+++ b/code/espurna/sensors/BMX280Sensor.h
@@ -22,6 +22,7 @@ class BMX280Sensor : public BaseSensor {
         // ---------------------------------------------------------------------
 
         void setAddress(unsigned char address) {
+            if (_address != address) _dirty = true;
             _address = address;
         }
 
@@ -32,6 +33,9 @@ class BMX280Sensor : public BaseSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             // Discover
             if (_address == 0) {
                 unsigned char addresses[] = {0x76, 0x77};
diff --git a/code/espurna/sensors/BaseSensor.h b/code/espurna/sensors/BaseSensor.h
index 2dbae59d..2790edd4 100644
--- a/code/espurna/sensors/BaseSensor.h
+++ b/code/espurna/sensors/BaseSensor.h
@@ -116,6 +116,7 @@ class BaseSensor {
         void detach(unsigned char gpio);
 
         int _error = 0;
+        bool _dirty = true;
         unsigned char _count = 0;
 
 
diff --git a/code/espurna/sensors/DallasSensor.h b/code/espurna/sensors/DallasSensor.h
index 6f977512..8fff6196 100644
--- a/code/espurna/sensors/DallasSensor.h
+++ b/code/espurna/sensors/DallasSensor.h
@@ -34,9 +34,11 @@ class DallasSensor : public BaseSensor {
         // ---------------------------------------------------------------------
 
         void setGPIO(unsigned char gpio, bool pullup = false) {
+            if (_gpio != gpio) _dirty = true;
+            if (_pullup != pullup) _dirty = true;
             _gpio = gpio;
-            _interval = SENSOR_READ_INTERVAL / 2;
             _pullup = pullup;
+            _interval = SENSOR_READ_INTERVAL / 2;
         }
 
         // ---------------------------------------------------------------------
@@ -46,6 +48,9 @@ class DallasSensor : public BaseSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             // OneWire
             if (_wire) delete _wire;
             _wire = new OneWire(_gpio);
diff --git a/code/espurna/sensors/EmonADC121Sensor.h b/code/espurna/sensors/EmonADC121Sensor.h
index 6e622993..dd1ae1e5 100644
--- a/code/espurna/sensors/EmonADC121Sensor.h
+++ b/code/espurna/sensors/EmonADC121Sensor.h
@@ -37,6 +37,7 @@ class EmonADC121Sensor : public EmonAnalogSensor {
         // ---------------------------------------------------------------------
 
         void setAddress(unsigned char address) {
+            if (_address != address) _dirty = true;
             _address = address;
         }
 
@@ -47,6 +48,9 @@ class EmonADC121Sensor : public EmonAnalogSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             // Discover
             if (_address == 0) {
                 unsigned char addresses[] = {0x50, 0x51, 0x52, 0x54, 0x55, 0x56, 0x58, 0x59, 0x5A};
diff --git a/code/espurna/sensors/EmonADS1X15Sensor.h b/code/espurna/sensors/EmonADS1X15Sensor.h
index 06f0157c..982a1e95 100644
--- a/code/espurna/sensors/EmonADS1X15Sensor.h
+++ b/code/espurna/sensors/EmonADS1X15Sensor.h
@@ -106,18 +106,22 @@ class EmonADS1X15Sensor : public EmonSensor {
         // ---------------------------------------------------------------------
 
         void setAddress(unsigned char address) {
+            if (_address != address) _dirty = true;
             _address = address;
         }
 
         void setType(unsigned char type) {
+            if (_type != type) _dirty = true;
             _type = type;
         }
 
         void setMask(unsigned char mask) {
+            if (_mask != mask) _dirty = true;
             _mask = mask;
         }
 
         void setGain(unsigned int gain) {
+            if (_gain != gain) _dirty = true;
             _gain = gain;
         }
 
@@ -128,6 +132,9 @@ class EmonADS1X15Sensor : public EmonSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             // Discover
             if (_address == 0) {
                 unsigned char addresses[] = {0x48, 0x49, 0x4A, 0x4B};
diff --git a/code/espurna/sensors/EmonAnalogSensor.h b/code/espurna/sensors/EmonAnalogSensor.h
index 4c053e6b..c6de3357 100644
--- a/code/espurna/sensors/EmonAnalogSensor.h
+++ b/code/espurna/sensors/EmonAnalogSensor.h
@@ -26,13 +26,16 @@ class EmonAnalogSensor : public EmonSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+            
             // Just one channel
             _count = _magnitudes;
 
             // Bit depth
             _resolution = INTERNAL_ADC_RESOLUTION;
 
-            // Init analog PIN
+            // Init analog PIN)
             pinMode(_gpio, INPUT);
 
             // Call the parent class method
diff --git a/code/espurna/sensors/EmonSensor.h b/code/espurna/sensors/EmonSensor.h
index 09774f9b..a77c3e99 100644
--- a/code/espurna/sensors/EmonSensor.h
+++ b/code/espurna/sensors/EmonSensor.h
@@ -29,15 +29,18 @@ class EmonSensor : public BaseSensor {
         }
 
         void setVoltage(double voltage) {
+            if (_voltage != voltage) _dirty = true;
             _voltage = voltage;
         }
 
-        void setReference(double ref) {
-            _reference = ref;
+        void setReference(double reference) {
+            if (_reference != reference) _dirty = true;
+            _reference = reference;
         }
 
-        void setCurrentRatio(double ratio) {
-            _current_ratio = ratio;
+        void setCurrentRatio(double current_ratio) {
+            if (_current_ratio != current_ratio) _dirty = true;
+            _current_ratio = current_ratio;
         }
 
         // ---------------------------------------------------------------------
diff --git a/code/espurna/sensors/MHZ19Sensor.h b/code/espurna/sensors/MHZ19Sensor.h
index 5df94507..e5709841 100644
--- a/code/espurna/sensors/MHZ19Sensor.h
+++ b/code/espurna/sensors/MHZ19Sensor.h
@@ -34,6 +34,8 @@ class MHZ19Sensor : public BaseSensor {
         }
 
         void setGPIO(unsigned char pin_rx, unsigned char pin_tx) {
+            if (_pin_rx != pin_rx) _dirty = true;
+            if (_pin_tx != pin_tx) _dirty = true;
             _pin_rx = pin_rx;
             _pin_tx = pin_tx;
         }
@@ -45,6 +47,9 @@ class MHZ19Sensor : public BaseSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             if (_serial) delete _serial;
 
             _serial = new SoftwareSerial(_pin_rx, _pin_tx, false, 256);
diff --git a/code/espurna/sensors/PMSX003Sensor.h b/code/espurna/sensors/PMSX003Sensor.h
index be8ccaac..3febcbd4 100644
--- a/code/espurna/sensors/PMSX003Sensor.h
+++ b/code/espurna/sensors/PMSX003Sensor.h
@@ -25,6 +25,8 @@ class PMSX003Sensor : public BaseSensor {
         }
 
         void setGPIO(unsigned char pin_rx, unsigned char pin_tx) {
+            if (_pin_rx != pin_rx) _dirty = true;
+            if (_pin_tx != pin_tx) _dirty = true;
             _pin_rx = pin_rx;
             _pin_tx = pin_tx;
         }
@@ -36,6 +38,9 @@ class PMSX003Sensor : public BaseSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             if (_serial) delete _serial;
             if (_pms) delete _pms;
 
diff --git a/code/espurna/sensors/SI7021Sensor.h b/code/espurna/sensors/SI7021Sensor.h
index 00750e3e..8840c9e1 100644
--- a/code/espurna/sensors/SI7021Sensor.h
+++ b/code/espurna/sensors/SI7021Sensor.h
@@ -32,6 +32,7 @@ class SI7021Sensor : public BaseSensor {
         // ---------------------------------------------------------------------
 
         void setAddress(unsigned char address) {
+            if (_address != address) _dirty = true;
             _address = address;
         }
 
@@ -42,6 +43,9 @@ class SI7021Sensor : public BaseSensor {
         // Initialization method, must be idempotent
         void begin() {
 
+            if (!_dirty) return;
+            _dirty = false;
+
             // Discover
             if (_address == 0) {
                 unsigned char addresses[] = {0x40};