diff --git a/recommendations/Costs.py b/recommendations/Costs.py
index 35fd237f..5554245f 100644
--- a/recommendations/Costs.py
+++ b/recommendations/Costs.py
@@ -841,7 +841,7 @@ class Costs:
             "labour_days": labour_days,
         }
 
-    def high_heat_electric_storage_heaters(self, number_heated_rooms):
+    def high_heat_electric_storage_heaters(self, number_heated_rooms, needs_cylinder):
 
         """
         We base the estimates for the cost of electric storage heaters on the cost per room as estimated by the
@@ -852,8 +852,12 @@ class Costs:
         :param number_heated_rooms: int, number of rooms to be heated
         """
 
-        # 500 is the cost of a dual immersion heater - a rough estimate
-        total_cost = 1200 * number_heated_rooms + 500
+        if needs_cylinder:
+            # 1000 is the cost of a new hot water cylinder
+            total_cost = 1200 * number_heated_rooms + 1000
+        else:
+            # 500 is the cost of a dual immersion heater - a rough estimate
+            total_cost = 1200 * number_heated_rooms + 500
         subtotal_before_vat = total_cost / (1 + self.VAT_RATE)
         vat = total_cost - subtotal_before_vat
 
diff --git a/recommendations/HeatingRecommender.py b/recommendations/HeatingRecommender.py
index 7c26fcb6..7dc4f8b2 100644
--- a/recommendations/HeatingRecommender.py
+++ b/recommendations/HeatingRecommender.py
@@ -858,7 +858,8 @@ class HeatingRecommender:
 
         # Upgrade to electric storage heaters
         costs = self.costs.high_heat_electric_storage_heaters(
-            number_heated_rooms=number_heated_rooms
+            number_heated_rooms=number_heated_rooms,
+            needs_cylinder=self.property.hotwater["system_type"] == "from main system"
         )
         if self.dual_heating:
             description = self.DUAL_HEATING_DESCRIPTIONS[
@@ -866,7 +867,7 @@ class HeatingRecommender:
             ]["hhr"]["recommendation_description"]
 
         else:
-            description = "Install high heat retention electric storage heaters."
+            description = "Install high heat retention electric storage heaters with an appropriate off-peak tariff."
 
         # We check the existing heating system and controls
         if (