The Viessmann 230V Cylinder Demand Terminal Box is a dedicated wiring interface designed to enable cylinder demand signals within compatible Viessmann heating systems. It ensures clear communication between the hot water cylinder controls and the boiler, allowing the system to prioritise domestic hot water production when required.

Ideal for systems using an indirect cylinder, this terminal box provides a neat and reliable connection point for installers, helping maintain efficient boiler operation and consistent hot water performance. Built to Viessmann’s high standards, it offers dependable functionality and simplified wiring for a wide range of domestic installations.

• Enables cylinder demand control
  Provides the signal required for the boiler to prioritise hot water production.

• 230V operation
  Designed for systems using a standard 230V hot water cylinder call-for-heat signal.

• Clean, simple wiring interface
  Offers a neat and organised connection point for installers.

• Reliable integration with Viessmann systems
  Ensures stable communication between the cylinder controls and the boiler.

• Supports efficient hot water regulation
  Helps the system respond quickly to hot water demand.

• Durable, installer‑friendly design
  Built to withstand regular use and provide long‑term reliability.

• Voltage:
  230V operation

• Function:
  Terminal interface to provide domestic hot water (DHW) demand signal

• Application:
  Connects hot water cylinder controls to compatible Viessmann boilers

• Installation:
  Wall‑mounted wiring box
  (Positioned near the cylinder or within the heating controls area)

• Compatibility:
  Designed for Viessmann heating systems supporting 230V cylinder demand inputs
  (Refer to boiler installation manual for specific model compatibility)

• Construction:
  Robust housing with clearly marked terminals for straightforward wiring