diff --git a/code/espurna/sensors/EmonADC121Sensor.h b/code/espurna/sensors/EmonADC121Sensor.h
index f06656c0..9e2f9a72 100644
--- a/code/espurna/sensors/EmonADC121Sensor.h
+++ b/code/espurna/sensors/EmonADC121Sensor.h
@@ -43,8 +43,9 @@ class EmonADC121Sensor : public EmonAnalogSensor {
         }
 
         void setAddress(unsigned char address) {
-            if (_address != address) _dirty = true;
+            if (_address == address) return;
             _address = address;
+            _dirty = true;
         }
 
         // ---------------------------------------------------------------------
diff --git a/code/espurna/sensors/EmonADS1X15Sensor.h b/code/espurna/sensors/EmonADS1X15Sensor.h
index c4056bc9..9c00a604 100644
--- a/code/espurna/sensors/EmonADS1X15Sensor.h
+++ b/code/espurna/sensors/EmonADS1X15Sensor.h
@@ -111,23 +111,27 @@ class EmonADS1X15Sensor : public EmonSensor {
         }
 
         void setAddress(unsigned char address) {
-            if (_address != address) _dirty = true;
+            if (_address == address) return;
             _address = address;
+            _dirty = true;
         }
 
         void setType(unsigned char type) {
-            if (_type != type) _dirty = true;
+            if (_type == type) return;
             _type = type;
+            _dirty = true;
         }
 
         void setMask(unsigned char mask) {
-            if (_mask != mask) _dirty = true;
+            if (_mask == mask) return;
             _mask = mask;
+            _dirty = true;
         }
 
         void setGain(unsigned int gain) {
-            if (_gain != gain) _dirty = true;
+            if (_gain == gain) return;
             _gain = gain;
+            _dirty = true;
         }
 
         // ---------------------------------------------------------------------
diff --git a/code/espurna/sensors/EmonSensor.h b/code/espurna/sensors/EmonSensor.h
index 17d5e1ba..2fa6b180 100644
--- a/code/espurna/sensors/EmonSensor.h
+++ b/code/espurna/sensors/EmonSensor.h
@@ -32,19 +32,31 @@ class EmonSensor : public BaseSensor {
         }
 
         void setVoltage(double voltage) {
-            if (_voltage != voltage) _dirty = true;
+            if (_voltage == voltage) return;
             _voltage = voltage;
+            _dirty = true;
         }
 
         void setReference(double reference) {
-            if (_reference != reference) _dirty = true;
+            if (_reference == reference) return;
             _reference = reference;
+            _dirty = true;
         }
 
         void setCurrentRatio(unsigned char channel, double current_ratio) {
             if (channel >= _channels) return;
-            if (_current_ratio[channel] != current_ratio) _dirty = true;
+            if (_current_ratio[channel] == current_ratio) return;
             _current_ratio[channel] = current_ratio;
+            _dirty = true;
+        }
+
+        void expectedPower(unsigned char channel, unsigned int expected) {
+            if (channel >= _channels) return;
+            unsigned int actual = _current[channel] * _voltage;
+            if (actual == 0) return;
+            if (expected == actual) return;
+            _current_ratio[channel] = _current_ratio[channel] * (expected / actual);
+            _dirty = true;
         }
 
         // ---------------------------------------------------------------------