diff --git a/main/fancontrol.c b/main/fancontrol.c
index b3ab800..9d1d9c4 100644
--- a/main/fancontrol.c
+++ b/main/fancontrol.c
@@ -99,8 +99,8 @@ static void timerCallback()
     cels_t tout = act_temp2();
 
     uint16_t old_tempSerial = gState.tempSerial;
-    float old_tin = gState.t_actual_in;
-    float old_tout = gState.t_actual_out;
+//    float old_tin = gState.t_actual_in;
+//    float old_tout = gState.t_actual_out;
 
     gState.tempSerial = act_temps_serial();
     gState.t_actual_in = tin;
@@ -108,6 +108,18 @@ static void timerCallback()
 
     gState.valid_t_actual_in = gState.valid_t_actual_out = tempSensorsOk;
 
+    if (gState.tempSerial != old_tempSerial) {
+        // measuring speed of temp change
+        for (int i = NUM_PREVIOUS_T_INS - 1; i > 0; i--) {
+            gState.previous_t_ins[i] = gState.previous_t_ins[i - 1];
+        }
+        if (gState.real_direction == MOTOR_DIR_IN) {
+            gState.previous_t_ins[0] = tin;
+        } else {
+            gState.previous_t_ins[0] = tout;
+        }
+    }
+
     // posun rolety
     if (gAct.blind) {
         if (gState.blind_position < gSettings.blind_time) {
@@ -218,14 +230,9 @@ static void timerCallback()
                             // Max time elapsed, switch even if the condition was not reached
                             do_switch = true;
                         } else {
-                            if (!gSettings.summer_mode && gState.tempSerial != old_tempSerial) {
+                            if (!gSettings.summer_mode) {
                                 // expecting some change in temps
-                                float speed;
-                                if (gState.real_direction == MOTOR_DIR_IN) {
-                                    speed = absf(tin - old_tin);
-                                } else {
-                                    speed = absf(tout - old_tout);
-                                }
+                                float speed = absf(gState.previous_t_ins[NUM_PREVIOUS_T_INS - 1] - gState.previous_t_ins[0]) / (float)NUM_PREVIOUS_T_INS;
 
                                 if (speed < gSettings.t_stop_speed) {
                                     ESP_LOGW(TAG, "Near-equilibrium reached, change dir!");
diff --git a/main/fancontrol.h b/main/fancontrol.h
index 1c93e3e..4e56057 100644
--- a/main/fancontrol.h
+++ b/main/fancontrol.h
@@ -27,6 +27,7 @@ enum recup_mode {
     RECUP_MODE_TEMP = 1,
 };
 
+#define NUM_PREVIOUS_T_INS 5
 
 struct FanControlState {
     /**
@@ -57,6 +58,8 @@ struct FanControlState {
     uint16_t tempSerial;
     cels_t t_actual_in;
     cels_t t_actual_out;
+    // buffer used to calculate the current temp change speed
+    cels_t previous_t_ins[NUM_PREVIOUS_T_INS];
 
     secs_t real_recup_time_in;
     secs_t real_recup_time_out;