diff --git a/kiln-tuner.py b/kiln-tuner.py
index 8868295..f9116d6 100755
--- a/kiln-tuner.py
+++ b/kiln-tuner.py
@@ -46,7 +46,7 @@ def recordprofile(csvfile, targettemp):
     try:
         stage = 'heating'
         if not config.simulate:
-            oven.output.heat(1, tuning=True)
+            oven.output.heat(0)
 
         while True:
             temp = oven.board.temp_sensor.temperature + \
@@ -73,7 +73,7 @@ def recordprofile(csvfile, targettemp):
     finally:
         # ensure we always shut the oven down!
         if not config.simulate:
-            oven.output.heat(0)
+            oven.output.cool(0)
 
 
 def line(a, b, x):
diff --git a/lib/oven.py b/lib/oven.py
index 35b7288..5d6b13a 100644
--- a/lib/oven.py
+++ b/lib/oven.py
@@ -27,10 +27,8 @@ class Output(object):
             log.warning(msg)
             self.active = False
 
-    def heat(self,sleepfor, tuning=False):
+    def heat(self,sleepfor):
         self.GPIO.output(config.gpio_heat, self.GPIO.HIGH)
-        if tuning:
-            return
         time.sleep(sleepfor)
 
     def cool(self,sleepfor):