diff --git a/src/core/helpers.cpp b/src/core/helpers.cpp
index 8098f93d8..25a8ed3db 100644
--- a/src/core/helpers.cpp
+++ b/src/core/helpers.cpp
@@ -1033,4 +1033,17 @@ float Helpers::numericoperator2scalefactor(int8_t numeric_operator) {
         return -numeric_operator;
 }
 
+int16_t Helpers::calc_dew(int16_t temp, uint8_t humi) {
+    if (humi == EMS_VALUE_UINT8_NOTSET || temp == EMS_VALUE_INT16_NOTSET) {
+        return EMS_VALUE_INT16_NOTSET;
+    }
+    const float k2 = 17.62;
+    const float k3 = 243.12;
+    const float t  = (float)temp / 10;
+    const float h  = (float)humi / 100;
+    int16_t     dt = (10 * k3 * (((k2 * t) / (k3 + t)) + log(h)) / (((k2 * k3) / (k3 + t)) - log(h)));
+    return dt;
+}
+
+
 } // namespace emsesp
diff --git a/src/core/helpers.h b/src/core/helpers.h
index 5758b08b8..cddc0c6a0 100644
--- a/src/core/helpers.h
+++ b/src/core/helpers.h
@@ -84,6 +84,7 @@ class Helpers {
     static uint8_t count_items(const char * const * list);
 
     static const char * translated_word(const char * const * strings, const bool force_en = false);
+    static int16_t      calc_dew(int16_t temp, uint8_t hum);
 
 #ifdef EMSESP_STANDALONE
     static char * ultostr(char * ptr, uint32_t value, const uint8_t base);
diff --git a/src/core/roomcontrol.cpp b/src/core/roomcontrol.cpp
index b047c4755..51fcadbb3 100644
--- a/src/core/roomcontrol.cpp
+++ b/src/core/roomcontrol.cpp
@@ -377,7 +377,7 @@ void Roomctrl::temperature(uint8_t addr, uint8_t dst, uint8_t hc) {
 
 // send telegram 0x047B only for RC100H
 void Roomctrl::humidity(uint8_t addr, uint8_t dst, uint8_t hc) {
-    int16_t dew  = calc_dew(remotetemp_[hc], remotehum_[hc]);
+    int16_t dew  = Helpers::calc_dew(remotetemp_[hc], remotehum_[hc]);
     int8_t  dew8 = EMS_VALUE_INT8_NOTSET;
     if (dew != EMS_VALUE_INT16_NOTSET) {
         dew8 = static_cast<int8_t>((dew >= 0 ? dew + 5 : dew - 5) / 10);
@@ -391,8 +391,8 @@ void Roomctrl::humidity(uint8_t addr, uint8_t dst, uint8_t hc) {
     data[5]  = 0x7B + hc;
     data[6]  = static_cast<uint8_t>(dew8);
     data[7]  = remotehum_[hc];
-    data[8]  = static_cast<uint8_t>(static_cast<uint16_t>(dew) >> 8);
-    data[9]  = static_cast<uint8_t>(static_cast<uint16_t>(dew) & 0xFF);
+    data[8]  = static_cast<uint8_t>(dew >> 8);
+    data[9]  = static_cast<uint8_t>(dew & 0x00FF);
     data[10] = EMSbus::calculate_crc(data, 10); // append CRC
     EMSuart::transmit(data, 11);
 }
@@ -440,17 +440,4 @@ void Roomctrl::replyF7(uint8_t addr, uint8_t dst, uint8_t offset, uint8_t typehh
     EMSuart::transmit(data, 10);
 }
 
-int16_t Roomctrl::calc_dew(int16_t temp, uint8_t humi) {
-    if (humi == EMS_VALUE_UINT8_NOTSET || temp == EMS_VALUE_INT16_NOTSET) {
-        return EMS_VALUE_INT16_NOTSET;
-    }
-    const float k2 = 17.62;
-    const float k3 = 243.12;
-    const float t  = (float)temp / 10;
-    const float h  = (float)humi / 100;
-    int16_t     dt = (10 * k3 * (((k2 * t) / (k3 + t)) + log(h)) / (((k2 * k3) / (k3 + t)) - log(h)));
-    return dt;
-}
-
-
 } // namespace emsesp
diff --git a/src/core/roomcontrol.h b/src/core/roomcontrol.h
index 2bc61c1e5..765982135 100644
--- a/src/core/roomcontrol.h
+++ b/src/core/roomcontrol.h
@@ -35,7 +35,6 @@ class Roomctrl {
         return (hc < 4 && remotetemp_[hc] != EMS_VALUE_INT16_NOTSET);
     }
     static void    set_timeout(uint8_t t);
-    static int16_t calc_dew(int16_t temp, uint8_t hum);
 
   private:
     static constexpr uint32_t SEND_INTERVAL = 15000; // 15 sec
diff --git a/src/devices/thermostat.cpp b/src/devices/thermostat.cpp
index 5aa0f4b84..7cc5fae20 100644
--- a/src/devices/thermostat.cpp
+++ b/src/devices/thermostat.cpp
@@ -818,7 +818,8 @@ void Thermostat::process_RemoteHumidity(std::shared_ptr<const Telegram> telegram
     if (telegram->read_value(dew, 2)) {
         has_update(dewtemperature_, dew);
     } else if (telegram->offset == 0 && telegram->message_length < 4) {
-        has_update(dewtemperature_, Roomctrl::calc_dew(tempsensor1_, humidity_));
+        dew = Helpers::calc_dew(tempsensor1_, humidity_);
+        has_update(dewtemperature_, dew);
     }
 }