diff --git a/etrago/cluster/gasclustering.py b/etrago/cluster/gasclustering.py
index <HASH>..<HASH> 100755
--- a/etrago/cluster/gasclustering.py
+++ b/etrago/cluster/gasclustering.py
@@ -146,8 +146,14 @@ def create_gas_busmap(etrago):
             save="network_ch4_" + kmean_gas_settings["bus_weight_tocsv"],

         )

     elif kmean_gas_settings["bus_weight_fromcsv"] is not None:

-        weight_ch4 = pd.Series.from_csv(kmean_gas_settings["bus_weight_fromcsv"])

-        weight_ch4.index = weight_ch4.index.astype(str)

+        # create DataFrame with uniform weightings for all ch4_buses

+        weight_ch4 = pd.DataFrame([1] * len(buses_ch4), index=buses_ch4.index)

+        loaded_weights = pd.read_csv(

+            kmean_gas_settings["bus_weight_fromcsv"], index_col=0

+        )

+        # load weights into previously created DataFrame

+        loaded_weights.index = loaded_weights.index.astype(str)

+        weight_ch4.loc[loaded_weights.index] = loaded_weights

     else:

         weight_ch4 = weighting_for_scenario(network_ch4.buses, save=False)
Updated deprecated from_csv to pandas.read_csv()