diff --git a/Puffer/module.php b/Puffer/module.php
index 96da367..bd7a07d 100644
--- a/Puffer/module.php
+++ b/Puffer/module.php
@@ -56,16 +56,6 @@ class Puffer extends IPSModule
         parent::ApplyChanges();
         $this->SetTimerInterval("Timer_Do_UserCalc_Boiler",$this->ReadPropertyInteger("Interval")*1000); 
 
-        $minVT = $this->ReadPropertyInteger("MinVT_Temp");  // z.B. 20
-        $maxVT = $this->ReadPropertyInteger("MaxVT_Temp");  // z.B. 80
-        $maxAT = $this->ReadPropertyInteger("MaxAT_Temp");  // z.B. 20
-        $minAT = $this->ReadPropertyInteger("MinAT_Temp");  // z.B. 0
-
-        $m = ($maxVT - $minVT) / ($minAT - $maxAT);
-        IPS_LogMessage("Puffer", "Steigung: " . $m);
-        $this->SetValue("Steigung", $m);
-
-
     }
 
     public function RequestAction($Ident, $Value)
@@ -166,7 +156,7 @@ class Puffer extends IPSModule
         $at = GetValue($this->ReadPropertyInteger("Aussentemp"));
         $this->SetValue("Aussentemperatur", $at);
 
-        IPS_LogMessage("Puffer", "aa " . $a);
+        IPS_LogMessage("Puffer", "aa " . $at);
         IPS_LogMessage("Puffer", "Property Aussentemp: " . $this->ReadPropertyInteger("Aussentemp"));
         IPS_LogMessage("Puffer", "Variable Aussentemperatur: " . $this->GetValue("Aussentemperatur"));
 
@@ -175,6 +165,10 @@ class Puffer extends IPSModule
         $maxVT = $this->ReadPropertyInteger("MaxVT_Temp");  // z.B. 80
         $maxAT = $this->ReadPropertyInteger("MaxAT_Temp");  // z.B. 20
         $minAT = $this->ReadPropertyInteger("MinAT_Temp");  // z.B. 0
+        $m = ($maxVT - $minVT) / ($minAT - $maxAT);
+        IPS_LogMessage("Puffer", "Steigung: " . $m);
+        $this->SetValue("Steigung", $m);
+
         if ($at < $minAT){
             $VT = $maxVT;
         } elseif ($at > $maxAT){