The Viessmann 4‑Pipe DHW Cylinder Connection Set is a dedicated hydraulic kit designed for Vitodens system boilers that use a 4‑pipe configuration to integrate an indirect domestic hot water (DHW) cylinder. This configuration enables fully independent operation of the DHW and heating circuits, improving system flexibility, heat‑up performance, and control accuracy.

This set is supplied with essential fittings and components required to connect the boiler to the DHW cylinder in a proper 4‑pipe arrangement. 

• Designed for 4‑pipe installations where the DHW and CH circuits operate independently. 

• Suitable for use with Vitodens system boilers, including Vitodens 100‑W B1HF and compatible PlusBus variants. 

• Provides correct flow and return fittings for connection to a DHW cylinder coil. 

• Includes a DHW cylinder sensor for accurate temperature monitoring and cylinder control. 

• Supports efficient hot water re‑heat by ensuring full boiler output is available to the cylinder via the 4‑pipe layout. 

• Ideal for systems using weather‑compensated heating where DHW production must remain unaffected by reduced CH flow temperatures. 

• DHW cylinder temperature sensor

• Flow and return fittings for DHW coil connection

• Installation fittings required for 4‑pipe integration

• Vitodens installations requiring independent hot water and heating circuit control

• Homes using unvented or open‑vent DHW cylinders with high re‑heat demand

• Systems wanting optimised DHW performance while using weather compensation for heating

• Installations upgrading from 2‑pipe S‑Plan/Y‑Plan layouts to Viessmann’s 4‑pipe configuration