diff --git a/actuators.py b/actuators.py
index 57b3071..c3379ac 100644
--- a/actuators.py
+++ b/actuators.py
@@ -100,7 +100,7 @@ actuators = {
     'humidifier': PIN(pin=17, initial=GPIO.HIGH, onstate=GPIO.LOW, offstate=GPIO.HIGH,
                       wattage=25),
     'heater2': PIN(pin=17, initial=GPIO.HIGH, onstate=GPIO.LOW, offstate=GPIO.HIGH,
-                      wattage=2000),    
-    'freezer': PIN(pin=14, initial=GPIO.HIGH, onstate=GPIO.LOW, offstate=GPIO.HIGH,
+                      wattage=400),
+    'freezer': PIN(pin=14, initial=GPIO.LOW, onstate=GPIO.HIGH, offstate=GPIO.LOW,
                       wattage=165),
 }
diff --git a/app.py b/app.py
index c1e7995..e37b723 100644
--- a/app.py
+++ b/app.py
@@ -149,17 +149,22 @@ def read_sensors():
     scantime = 0.5
     periodic_state_every_s = 5
     periodic_state_every_loop = int(periodic_state_every_s/scantime)
+    last_scan = 0
     while True:
-        sensors.read()
-        socketio.emit('sensors', (sensors.get(),))
-        if periodic_counter % periodic_state_every_loop == 0:
-            ## peridoic refresh other data, too, like:
-            # - current phase (time in this phase)
-            # - actuators (consumption)
-            # Issuing a full state update is easiest
-            updateState()
-        periodic_counter += 1
-        sleep(scantime)
+        # This should be more precise than sleep(0.5) and gives the OS the
+        # control to do other things
+        sleep(0.01)
+        if perf_counter() - last_scan > scantime:
+            sensors.read()
+            socketio.emit('sensors', (sensors.get(),))
+            if periodic_counter % periodic_state_every_loop == 0:
+                ## peridoic refresh other data, too, like:
+                # - current phase (time in this phase)
+                # - actuators (consumption)
+                # Issuing a full state update is easiest
+                updateState()
+            periodic_counter += 1
+            last_scan = perf_counter()
 
 import threading
 if __name__ == '__main__':
diff --git a/phasectrl.py b/phasectrl.py
index 2e218a1..a0cf219 100644
--- a/phasectrl.py
+++ b/phasectrl.py
@@ -180,7 +180,7 @@ class State():
                 response = ctrl.apply(self.envdata['sensors'][ctrl.input_label][0])
                 actuators[controller].enable(response)
             except Exception as e:
-                print(f"UNKNOWN BUG HERE in run_step {e}")
+                print(f"UNKNOWN BUG HERE in run_step {e} on controller {ctrl}")
         if self.check():
             if self.next() is None:
                 return True
diff --git a/sensors.py b/sensors.py
index 14e5b29..ea56080 100644
--- a/sensors.py
+++ b/sensors.py
@@ -220,7 +220,7 @@ class Sensors():
             'H_ext2':     AHT40('Humidity'),
             'heater':     GPIOState(22),
             'humidifier/heater2': GPIOState(17),
-            'freezer':    GPIOState(14),
+            'freezer':    GPIOState(14, transform=lambda x: x),
             'fan':        GPIOState(27),
         }