 
 boolean isSensorFaulty(float humidity) {
     if (isnan(humidity)) {
-        return false; // do not consider missing sensor as faulty
+        return true;
     } else  if (humidity > 98.8 || humidity < 1.2) {
         return true;
     } else {

    lcd.setCursor(0, 0);
    lcd.print("***FanControl***");
    lcd.setCursor(0, 1);
    lcd.print("***   2.03   ***");
    time = millis() - time;
    Serial.print("Took "); Serial.print(time); Serial.println(" ms");
    lcd.setBacklight(WHITE);

    pinMode(DHT_PIN_OUTSIDE_2, INPUT_PULLUP);
    pinMode(DHT_PIN_INSIDE, INPUT_PULLUP);
    pinMode(LED_PIN, OUTPUT);
    ledOn();

    attachInterrupt(digitalPinToInterrupt(FAN_PIN_RPM), rpm, RISING);

