diff --git a/models/operation/components.py b/models/operation/components.py
index d24a975..f073839 100644
--- a/models/operation/components.py
+++ b/models/operation/components.py
@@ -51,6 +51,7 @@ class Building(OperationComponent):
 class Boiler(OperationComponent):
     type: Optional[str] = None
     carnot_efficiency_factor: Optional[float] = None
+    fuel_boiler_efficiency: Optional[float] = None
 
 
 @dataclass
diff --git a/models/operation/model_base.py b/models/operation/model_base.py
index f2315ea..bca5fe3 100644
--- a/models/operation/model_base.py
+++ b/models/operation/model_base.py
@@ -60,7 +60,7 @@ def setup_building_params(self):
                                                       static=False)
 
     def setup_space_heating_params(self):
-        self.fuel_boiler_efficiency = 1  # TODO specify as input??
+        self.fuel_boiler_efficiency = self.scenario.boiler.fuel_boiler_efficiency
         self.SpaceHeatingHourlyCOP = self.calc_cop(
             outside_temperature=self.scenario.region.temperature,
             supply_temperature=self.scenario.building.supply_temperature,
diff --git a/tests/operation/input/OperationScenario_Component_Boiler.xlsx b/tests/operation/input/OperationScenario_Component_Boiler.xlsx
index d016c03..86a69cb 100644
Binary files a/tests/operation/input/OperationScenario_Component_Boiler.xlsx and b/tests/operation/input/OperationScenario_Component_Boiler.xlsx differ