diff --git a/frappy_psi/ccracks.py b/frappy_psi/ccracks.py
index d16d5616..a8eab23c 100644
--- a/frappy_psi/ccracks.py
+++ b/frappy_psi/ccracks.py
@@ -3,6 +3,7 @@ from glob import glob
 from pathlib import Path
 from configparser import ConfigParser
 from frappy.errors import ConfigError
+from frappy.config import Param
 
 
 class Rack:
@@ -14,6 +15,7 @@ class Rack:
         sections = {}
         self.config = {}
         files = glob(str(instpath / '*.ini'))
+        # TODO: why may we accept several rack configs?
         for filename in files:
             parser = ConfigParser()
             parser.optionxform = str
@@ -24,7 +26,7 @@ class Rack:
                     raise ConfigError(f'duplicate {section} section in {filename} and {prev}')
                 sections[section] = filename
                 self.config.update(parser.items(section))
-        if 'rack' not in sections:
+        if 'config' not in sections:
             raise ConfigError(f'no rack found in {instpath}')
         self.props = {}  # dict (<property>, <method>) of value
         self.mods = {}  # dict (<property>, <method>) of list of <cfg>
@@ -39,7 +41,7 @@ class Rack:
             else:
                 # set prop in current module
                 if not mod.get(prop):  # do not override given and not empty property
-                    mod[prop] = value
+                    mod[prop] = Param(value)
 
     def fix_props(self, method, **kwds):
         for prop, value in kwds.items():
@@ -48,12 +50,12 @@ class Rack:
             self.props[prop, method] = value
             # set property in modules to be fixed
             for mod in self.mods.get((prop, method), ()):
-                mod[prop] = value
+                mod[prop] = Param(value)
 
     def lakeshore(self, ls_uri=None, io='ls_io', dev='ls', model='336', **kwds):
         Mod = self.modfactory
         self.fix_props('lakeshore', io=io, device=dev)
-        self.ls_model = model
+        self.ls_model = self.config.get('ls_model', model)
         self.ls_dev = dev
         ls_uri = ls_uri or self.config.get('ls_uri')
         Mod(io, cls=f'frappy_psi.lakeshore.IO{self.ls_model}',
@@ -129,7 +131,7 @@ class Rack:
         Mod = self.modfactory
         hepump_type = hepump_type or self.config.get('hepump_type', 'no')
         Mod(nv, 'frappy_psi.ccu4.NeedleValveFlow', 'flow from flow sensor or pump pressure',
-            flow_sensor=flow_sensor, pressure=pump_pressure, io=ccu_io, **kwds)
+            flow_sensor=flow_sensor, pressure=pump_pressure, io=ccu_io, pump_type=hepump_type, **kwds)
         Mod(pump_pressure, 'frappy_psi.ccu4.Pressure', 'He pump pressure', io=ccu_io)
         if hepump_type == 'no':
             print('no pump, no flow meter - using flow from pressure alone')
@@ -137,7 +139,7 @@ class Rack:
         hepump_uri = hepump_uri or self.config['hepump_uri']
         Mod(hepump_io, 'frappy.io.BytesIO', 'He pump connection', uri=hepump_uri)
         Mod(hepump, 'frappy_psi.hepump.HePump', 'He pump', pump_type=hepump_type,
-            valvemotor=hepump_mot, valve=hepump_valve, flow=nv)
+            valvemotor=hepump_mot, valve=hepump_valve)
         Mod(hepump_mot, 'frappy_psi.hepump.Motor', 'He pump valve motor', io=hepump_io, maxcurrent=2.8)
         Mod(hepump_valve, 'frappy_psi.butterflyvalve.Valve', 'He pump valve', motor=hepump_mot)
         Mod(flow_sensor, 'frappy_psi.sensirion.FlowSensor', 'Flow Sensor', io=hepump_io, nsamples=160)