Retrofit kit (1) for an existing central
heating system (2), wherein the central
heating system (2) comprises at least one primary heat source (3) operable by means of fuels, in particular a boiler and / or a gas boiler, at least one
heat exchanger (4), preferably a radiator for heating a building, and at least one domestic
hot water storage tank (5), wherein a
heat transfer fluid (6), in particular water, can be heated by means of the primary heat source (3), wherein the
heat transfer fluid (6) can be conveyed to and / or through the
heat exchanger (4) by means of a
heat pump (7), and wherein the
heat transfer fluid (6) can be conveyed to the domestic
hot water storage tank (5) for heating domestic hot water (9) temporarily stored in the domestic
hot water storage tank (5), namely for heat transfer from the
heat transfer fluid (6) to the domestic hot water (9) through or adjacent to the domestic hot
water storage tank (5),wherein the primary heat source (3) has a central heating control and / or regulation device (10) for its control and / or regulation, wherein the retrofit kit (1) and / or the central
heating system (2) has at least one electrically operated
heat pump (11), wherein the
heat transfer fluid (6) can be heated by means of the
heat pump (11), wherein the
heat transfer fluid (6) can be conveyed to and / or through the heat pump (11) for its heating, and wherein the heat transfer fluid (6) can be conveyed to and / or through the primary heat source (3) by means of the heating pump (7) and / or the storage pump (8), characterized in that the retrofit kit (1) has a temperature sensor (13.1) and a separate heat pump control and / or regulation device (14) for the heat pump (11), wherein the temperature sensor (13.1) is connected to the separate heat pump control and / or regulation device (14) for control / is connected or connectable via
signal and / or data technology,wherein the heat pump (11) is connected and / or connectable to the separate heat pump control and / or regulation device (14) for control purposes, wherein the separate heat pump control and / or regulation device (14) is designed and / or implemented such that the heat pump (11) is controlled based on the actual domestic hot
water temperature (T) measured by means of the temperature sensor (13.1) in a lower area of the domestic hot
water storage tank (5) or adjacent to this lower area of the domestic hot
water storage tank (5). B1 ) is controllable and / or adjustable, wherein the temperature sensor (13.1) is used as a first temperature sensor (13.1) for determining a first actual domestic hot
water temperature (T B1 ) is implemented, wherein a second temperature sensor (13.2) is located in a vertically viewed middle or upper area of the domestic hot
water storage tank (5) for measuring and / or determining a second actual domestic hot
water temperature (T B2) is arranged, wherein the second temperature sensor (13.2) is connected to the central heating control and / or regulating device (10) in a control /
signal / and / or data-related manner, wherein the central heating control and / or regulating device (10) is designed and / or implemented such that the primary heat source (3) is adjusted depending on the second actual domestic hot water temperature (T B2 ) is controllable and / or adjustable, wherein the separate heat pump control and / or regulation device (14) is designed and / or implemented such that the heat pump (11) can be operated and / or activated for heating the heat transfer fluid (6) with the aid of the separate heat pump control and / or regulation device (14) when the first actual domestic hot water temperature (T) measured, determined and / or calculated with the aid of the first temperature sensor (13.1) B1 ) a first limiting temperature (T B1G ) falls below.