Viessmann DHW Heat Exchanger VIESSMANN7828745

The Viessmann DHW heat exchanger (part number 7828745) is a component used in Viessmann heating and hot water appliances. It transfers heat from the primary circuit to the domestic hot water supply, separating the heating water from the potable water. This part is also identified by the alternative number 1779016656.

• Reduced domestic hot water temperature or inconsistent hot water supply.
• Visible leaks or weeping from the heat exchanger body or connections.
• Scale build-up causing restricted flow or noisy operation.
• Repeated boiler lockouts or error codes related to DHW performance.
• Corrosion or physical damage to the heat exchanger surfaces.

• Check the part number 7828745 against your appliance's documentation or existing component.
• Confirm the alternative number 1779016656 matches the part you are replacing.
• Check whether a gasket or seal kit is required for your specific appliance.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.