diff --git a/ess/lib_tw.py b/ess/lib_tw.py
index e83f8ef20aa33e914e5a3be59e298ec2791abfce..857b41414e65601afd4f08f906bcabf847783d6e 100644
--- a/ess/lib_tw.py
+++ b/ess/lib_tw.py
@@ -952,13 +952,13 @@ def partran_end_all(file_name_in_all,file_name_out):
 
 
 def _update_field_map_dict(dictionary,folder_path):
-    import os
+    import os,logging
     for filename in os.listdir(folder_path):
         if filename.split('.')[-1]=='edz': # only 1D for now..
             key=filename.split('.')[0]
             if key not in dictionary: # do not override user selection
                 dictionary[key]=os.path.join(folder_path,filename)
-                print key,':',dictionary[key]
+                logging.debug(' Found field map {}: {}'.format(key,dictionary[key]))
 
 #-------- Obsolete classes and functions