Buffer tank Vaillant SPU-1 200 l – indirect heating storage, 200 liters

Vaillant SPU-1 200 l is a 200-liter indirect heating buffer tank designed to store thermal energy and stabilise hydraulic cycles in central heating systems. It is intended for integration with boilers, heat pumps or solar thermal systems where short-term heat storage is needed to reduce short-cycling, even out temperature fluctuations and improve overall system efficiency. The tank is a compact solution for residential and light-commercial installations that require an intermediate storage volume to optimise heat source operation.

Advantages

The buffer tank provides temporal separation between heat generation and heat demand, which reduces on/off cycles of boilers and heat pumps and extends equipment life. Its 200 l volume offers sufficient storage for many single-family homes and small commercial spaces, improving the stability of flow temperatures and enabling smoother control of heating circuits. Designed for indirect heating use, the tank supports integration with different heat sources and contributes to more consistent room comfort and efficient system performance.

Suitable for

• Single-family homes with gas, oil or electric boilers
• Heat pump systems requiring hydraulic buffering
• Solar thermal installations combined with a conventional heat source
• Light-commercial buildings with intermittent heat demand

Key specifications

• Nominal volume: 200 litres
• Type: indirect heating buffer/storage tank
• Application: central heating system thermal storage
• Integration: suitable for boilers, heat pumps and solar thermal systems
• Primary benefit: reduces short-cycling and stabilises hydraulic cycles

How to use

Install the buffer tank in the heating circuit according to the system design, positioning it to allow correct hydraulic connections to the heat source and distribution circuits. Ensure proper piping, pumps and control valves are used to manage flow between the tank and heat generators. The tank is connected indirectly; a heat exchanger or primary loop circulates fluid between the heat source and tank. Commissioning should include pressure and leak tests, filling with the appropriate heat-transfer fluid, and setting control parameters so the buffer supports the heat source without causing unwanted heat losses.

Usage recommendations

Place the tank on a stable, level surface with sufficient access for maintenance. Insulate piping and the surrounding area to minimise standby losses. Coordinate tank volume and control strategy with the heat source manufacturer or a qualified installer to achieve the intended reduction in short-cycling and improved efficiency.