diff --git a/stixcore/processing/L1toL2.py b/stixcore/processing/L1toL2.py
index e2bbd50f..5f838413 100644
--- a/stixcore/processing/L1toL2.py
+++ b/stixcore/processing/L1toL2.py
@@ -104,16 +104,20 @@ def process_type(files, *, processor, soopmanager, spice_kernel_path, config):
             for l2 in tmp.from_level1(
                 l1, parent=complete_file_name, idlprocessor=idlprocessor, ecc_manager=ecc_manager
             ):
-                new_files = processor.write_fits(l2)
-                all_files.extend(new_files)
+                try:
+                    new_files = processor.write_fits(l2)
+                    all_files.extend(new_files)
+                # we have to check in the for loop as some products might create
+                # multiple files and some of them might be combinable and some not
+                except NotCombineException as nc:
+                    logger.warning(nc)
+
             # if a batch of X files have summed up run the IDL processing
             if idlprocessor.opentasks >= max_idlbatch:
                 all_files.extend(idlprocessor.process())
                 idlprocessor = SSWIDLProcessor(processor)
         except (NoMatchError, KeyError):
             logger.warning("No L2 product match for product %s", l1)
-        except NotCombineException as nc:
-            logger.info(nc)
         except Exception as e:
             logger.error("Error processing file %s", file, exc_info=True)
             logger.error("%s", e)
diff --git a/stixcore/products/CAL/energy.py b/stixcore/products/CAL/energy.py
index e24a8b03..9b3e6053 100644
--- a/stixcore/products/CAL/energy.py
+++ b/stixcore/products/CAL/energy.py
@@ -13,6 +13,7 @@
 from stixcore.calibration.ecc_post_fit import ecc_post_fit_on_fits
 from stixcore.calibration.elut_manager import ELUTManager
 from stixcore.config.config import CONFIG
+from stixcore.products.level0.scienceL0 import NotCombineException
 from stixcore.products.product import EnergyChannelsMixin, GenericProduct, L2Mixin
 from stixcore.time import SCETimeRange
 from stixcore.util.logging import get_logger
@@ -412,3 +413,6 @@ def from_level1(cls, l1product, parent="", idlprocessor=None, ecc_manager=None):
             # end of for each spectrum
 
         return products
+
+    def __add__(self, other):
+        raise NotCombineException(f"Tried to combine 2 cal_energy products: \n{self} and \n{other}")