diff --git a/config/example-extras.cfg b/config/example-extras.cfg
index 29e42455..ca57f065 100644
--- a/config/example-extras.cfg
+++ b/config/example-extras.cfg
@@ -133,15 +133,18 @@
 #   The amount of time (in seconds) that the heating_gain must be met
 #   in before an error is raised. The default is 20 seconds for
 #   extruders and 60 seconds for heater_bed.
-#hysteresis: 10
+#hysteresis: 5
 #   The difference between the target temperature and the current
 #   temperature for the heater to be considered within range of the
-#   target temperature. The default is 10.
-#check_time: 15
-#   The amount of time (in seconds) a heater that has reached the
-#   target temperature (as defined by the hysteresis field) may fall
-#   outside the target temperature range before an error is
-#   raised. The default is 15.
+#   target temperature. The default is 5.
+#max_error: 120
+#   The maximum temperature difference a heater that falls outside the
+#   target temperature range may accumulate before an error is
+#   raised. For example, if the target temperature is 200, the
+#   hysteresis is 5, the max_error is 120, and the temperature is
+#   reported at 185 degrees for 12 seconds then an error would be
+#   raised (or 24 seconds at 190, or 120 seconds at 194, etc.). The
+#   default is 120.
 
 
 # Multi-stepper axes. On a cartesian style printer, the stepper
diff --git a/klippy/extras/verify_heater.py b/klippy/extras/verify_heater.py
index 4a30c241..a6eae5a1 100644
--- a/klippy/extras/verify_heater.py
+++ b/klippy/extras/verify_heater.py
@@ -11,8 +11,8 @@ class HeaterCheck:
         self.printer = config.get_printer()
         self.heater_name = config.get_name().split()[1]
         self.heater = None
-        self.hysteresis = config.getfloat('hysteresis', 10., above=0.)
-        self.check_time = config.getfloat('check_time', 15., minval=1.)
+        self.hysteresis = config.getfloat('hysteresis', 5., minval=0.)
+        self.max_error = config.getfloat('max_error', 120., minval=0.)
         self.heating_gain = config.getfloat('heating_gain', 2., above=0.)
         default_gain_time = 20.
         if self.heater_name == 'heater_bed':
@@ -20,7 +20,7 @@ class HeaterCheck:
         self.check_gain_time = config.getfloat(
             'check_gain_time', default_gain_time, minval=1.)
         self.met_target = False
-        self.last_target = self.goal_temp = 0.
+        self.last_target = self.goal_temp = self.error = 0.
         self.fault_systime = self.printer.get_reactor().NEVER
     def printer_state(self, state):
         if state == 'connect':
@@ -33,12 +33,13 @@ class HeaterCheck:
         temp, target = self.heater.get_temp(eventtime)
         if temp >= target - self.hysteresis:
             # Temperature near target - reset checks
-            if not self.met_target:
+            if not self.met_target and target:
                 logging.info("Heater %s within range of %.3f",
                              self.heater_name, target)
             self.met_target = True
-            self.fault_systime = eventtime + self.check_time
+            self.error = 0.
         elif self.met_target:
+            self.error += (target - self.hysteresis) - temp
             if target != self.last_target:
                 # Target changed - reset checks
                 logging.info("Heater %s approaching new target of %.3f",
@@ -46,7 +47,7 @@ class HeaterCheck:
                 self.met_target = False
                 self.goal_temp = temp + self.heating_gain
                 self.fault_systime = eventtime + self.check_gain_time
-            elif eventtime >= self.fault_systime:
+            elif self.error >= self.max_error:
                 # Failure due to inability to maintain target temperature
                 return self.heater_fault()
         elif temp >= self.goal_temp: