diff --git a/config.py.EXAMPLE b/config.py.EXAMPLE
index 242e505..bf15d37 100644
--- a/config.py.EXAMPLE
+++ b/config.py.EXAMPLE
@@ -26,6 +26,8 @@ gpio_heat = 11  # Switches zero-cross solid-state-relay
 gpio_cool = 10  # Regulates PWM for 12V DC Blower
 gpio_air  = 9   # Switches 0-phase det. solid-state-relay
 
+heater_invert = 0 # switches the polarity of the heater control
+
 ### Inputs
 gpio_door = 18
 
diff --git a/lib/oven.py b/lib/oven.py
index a294a99..3c37d73 100644
--- a/lib/oven.py
+++ b/lib/oven.py
@@ -146,11 +146,17 @@ class Oven (threading.Thread):
         if value:
             self.heat = 1.0
             if gpio_available:
-                GPIO.output(config.gpio_heat, GPIO.LOW)
+               if config.heater_invert:
+               	 GPIO.output(config.gpio_heat, GPIO.LOW)
+               else:
+                 GPIO.output(config.gpio_heat, GPIO.HIGH)
         else:
             self.heat = 0.0
             if gpio_available:
-                GPIO.output(config.gpio_heat, GPIO.HIGH)
+               if config.heater_invert:
+               	 GPIO.output(config.gpio_heat, GPIO.HIGH)
+               else:
+                 GPIO.output(config.gpio_heat, GPIO.LOW)
 
     def set_cool(self, value):
         if value: