diff --git a/ESPtermostat.ino b/ESPtermostat.ino
index 783f9f1..fbea8ff 100644
--- a/ESPtermostat.ino
+++ b/ESPtermostat.ino
@@ -172,9 +172,13 @@ void thermostatCheck(){
 }
 
 void readSensor() {
+  float tempC = sensor.getTempCByIndex(0);
+  
+  if(tempC != DEVICE_DISCONNECTED_C){
     // read the actual temperature after it's been converted
-    temperature = sensor.getTempCByIndex(0) + CORRECTION;
+    temperature = tempC + CORRECTION;
     // do what you need with the temperature here
+  }
   metrics = "temp ";
   metrics += temperature;
 }