https://community.viessmann.de/t5/Gas/Heating-a-water-tank/m-p/638850#M148064 <P>I installed a new Viessmann Vitodens 050 W in 2025.</P><P>It heats a hot water tank, which then supplies heat to the underfloor system, as well as providing domestic hot water to the house.</P><P>The circulation pump is permanently running in order to keep the tank up to the required temperature.</P><P>If a thermostatic sensor were placed in the tank and connected to the boiler, there would be no reason to keep the pump running, thus saving up to 300 kWhr per year.</P><P>Please advise if this modification is possible</P> Wed, 07 Oct 2026 15:56:36 GMT Raylund 2026-10-07T15:56:36Z https://community.viessmann.de/t5/Gas/Heating-a-water-tank/m-p/638850#M148064 <P>I installed a new Viessmann Vitodens 050 W in 2025.</P><P>It heats a hot water tank, which then supplies heat to the underfloor system, as well as providing domestic hot water to the house.</P><P>The circulation pump is permanently running in order to keep the tank up to the required temperature.</P><P>If a thermostatic sensor were placed in the tank and connected to the boiler, there would be no reason to keep the pump running, thus saving up to 300 kWhr per year.</P><P>Please advise if this modification is possible</P> Wed, 07 Oct 2026 15:56:36 GMT https://community.viessmann.de/t5/Gas/Heating-a-water-tank/m-p/638850#M148064 Raylund 2026-10-07T15:56:36Z