diff --git a/backend/documents_parser/extractor.py b/backend/documents_parser/extractor.py
index 8e19d05c..eb132a2d 100644
--- a/backend/documents_parser/extractor.py
+++ b/backend/documents_parser/extractor.py
@@ -573,7 +573,8 @@ class PasHubRdSapSiteNotesExtractor:
         )
 
     def _parse_water_heating(self, data: List[str]) -> WaterHeating:
-        thickness_raw = self._get_in(data, "Insulation Thickness (mm):")
+        thickness_raw = self._get_in(data, "Insulation Thickness (mm):") or self._get_in(data, "Thickness:")
+        thickness_mm = int(thickness_raw.split()[0]) if thickness_raw else None
         return WaterHeating(
             type=self._get_in(data, "Water Heating Type:") or "",
             system=self._get_in(data, "Water Heating System:") or "",
@@ -582,7 +583,7 @@ class PasHubRdSapSiteNotesExtractor:
                 data, "Cylinder Measured Heat Loss:"
             ),
             insulation_type=self._get_in(data, "Insulation Type:"),
-            insulation_thickness_mm=int(thickness_raw) if thickness_raw else None,
+            insulation_thickness_mm=thickness_mm,
             has_thermostat=self._optional_bool_in(data, "Cylinder Thermostat:"),
         )
 
diff --git a/backend/documents_parser/tests/test_extractor.py b/backend/documents_parser/tests/test_extractor.py
index 6ca35110..99e46eb5 100644
--- a/backend/documents_parser/tests/test_extractor.py
+++ b/backend/documents_parser/tests/test_extractor.py
@@ -377,9 +377,18 @@ class TestWaterHeatingCylinderThickness:
             load_text_fixture_2()
         ).extract_heating_and_hot_water()
 
+    @pytest.fixture
+    def hhw_no_cylinder(self) -> HeatingAndHotWater:
+        return PasHubRdSapSiteNotesExtractor(
+            load_text_fixture()
+        ).extract_heating_and_hot_water()
+
     def test_cylinder_insulation_thickness_mm(self, hhw: HeatingAndHotWater) -> None:
         assert hhw.water_heating.insulation_thickness_mm == 38
 
+    def test_cylinder_insulation_thickness_mm_absent(self, hhw_no_cylinder: HeatingAndHotWater) -> None:
+        assert hhw_no_cylinder.water_heating.insulation_thickness_mm is None
+
 
 class TestHeatingAndHotWater:
     @pytest.fixture