diff --git a/klippy/extruder.py b/klippy/extruder.py
index 45ed3bfc..44315f9b 100644
--- a/klippy/extruder.py
+++ b/klippy/extruder.py
@@ -252,11 +252,10 @@ def get_printer_extruders(printer):
     return out
 
 def get_printer_heater(printer, name):
-    if name == 'heater_bed':
-        return printer.objects.get(name)
+    if name == 'heater_bed' and name in printer.objects:
+        return printer.objects[name]
     if name == 'extruder':
         name = 'extruder0'
-    extruder = printer.objects.get(name)
-    if extruder is None:
-        return None
-    return extruder.get_heater()
+    if name.startswith('extruder') and name in printer.objects:
+        return printer.objects[name].get_heater()
+    raise printer.config_error("Unknown heater '%s'" % (name,))
diff --git a/klippy/fan.py b/klippy/fan.py
index 05e883a5..cd5c14c1 100644
--- a/klippy/fan.py
+++ b/klippy/fan.py
@@ -41,8 +41,6 @@ class PrinterHeaterFan:
         self.fan = PrinterFan(printer, config)
         heater = config.get("heater", "extruder0")
         self.heater = extruder.get_printer_heater(printer, heater)
-        if self.heater is None:
-            raise config.error("Unknown heater '%s'" % (heater,))
         self.heater_temp = config.getfloat("heater_temp", 50.0)
         printer.reactor.register_timer(self.callback, printer.reactor.NOW)
     def callback(self, eventtime):
diff --git a/klippy/klippy.py b/klippy/klippy.py
index 60bb9359..286e56f4 100644
--- a/klippy/klippy.py
+++ b/klippy/klippy.py
@@ -6,7 +6,7 @@
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import sys, optparse, ConfigParser, logging, time, threading
 import util, reactor, queuelogger, msgproto, gcode
-import pins, mcu, chipmisc, toolhead, extruder, fan, heater
+import pins, mcu, chipmisc, toolhead, extruder, heater, fan
 
 message_ready = "Printer is ready"
 
@@ -123,6 +123,7 @@ class ConfigLogger():
         self.lines.append(data.strip())
 
 class Printer:
+    config_error = ConfigParser.Error
     def __init__(self, input_fd, bglogger, start_args):
         self.bglogger = bglogger
         self.start_args = start_args
@@ -166,13 +167,13 @@ class Printer:
         config_file = self.start_args['config_file']
         res = self.fileconfig.read(config_file)
         if not res:
-            raise ConfigParser.Error("Unable to open config file %s" % (
+            raise self.config_error("Unable to open config file %s" % (
                 config_file,))
         if self.bglogger is not None:
             ConfigLogger(self.fileconfig, self.bglogger)
         # Create printer components
         config = ConfigWrapper(self, 'printer')
-        for m in [pins, mcu, chipmisc, toolhead, extruder, fan, heater]:
+        for m in [pins, mcu, chipmisc, toolhead, extruder, heater, fan]:
             m.add_printer_objects(self, config)
         self.mcu = self.objects['mcu']
         # Validate that there are no undefined parameters in the config file
@@ -180,12 +181,12 @@ class Printer:
         for section in self.fileconfig.sections():
             section = section.lower()
             if section not in valid_sections:
-                raise ConfigParser.Error("Unknown config file section '%s'" % (
+                raise self.config_error("Unknown config file section '%s'" % (
                     section,))
             for option in self.fileconfig.options(section):
                 option = option.lower()
                 if (section, option) not in self.all_config_options:
-                    raise ConfigParser.Error(
+                    raise self.config_error(
                         "Unknown option '%s' in section '%s'" % (
                             option, section))
     def _connect(self, eventtime):
@@ -196,7 +197,7 @@ class Printer:
             self.mcu.connect()
             self.gcode.set_printer_ready(True)
             self.state_message = message_ready
-        except (ConfigParser.Error, pins.error) as e:
+        except (self.config_error, pins.error) as e:
             logging.exception("Config error")
             self.state_message = "%s%s" % (str(e), message_restart)
             self.reactor.update_timer(self.stats_timer, self.reactor.NEVER)