CDWT-500L – Fast Boiler Tank & Buffer Tank in One Unit – 500 Litres (300L + 200L), Duplex 2205 Stainless Steel, with Spiral Coil for Heat Pump

The CDWT-500L Fast Boiler & Buffer Tank Combination from Coolmark is an innovative 2-in-1 solution that combines a domestic hot water boiler and buffer tank in one compact, robust stainless steel housing. Specially designed for use with heat pumps, solar energy systems, and hybrid heating installations, this unit offers maximum efficiency, space savings, and installation convenience.

The tank is divided into two separate compartments:

• A 300-litre boiler tank for domestic hot water

• A 200-litre buffer tank for space heating or extra storage

Both tanks are made from Duplex 2205 stainless steel, a high-grade alloy known for its exceptional resistance to corrosion, high temperatures, and pressure. This makes the boiler-buffer combination suitable for both residential and commercial applications with intensive use.

The integrated spiral coil heat exchanger has a surface area of 3.3 m² and is optimised for low-temperature sources such as air-to-water heat pumps. This ensures fast and efficient heat transfer from the heating system to the domestic hot water.

Thanks to the high-quality 50 mm PUR rigid foam insulation around both compartments, heat losses are kept to a minimum, contributing to lower energy consumption and higher system efficiency.

Key benefits:

• 2-in-1 solution: boiler (300L) + buffer tank (200L) in one compact unit

• Duplex 2205 stainless steel: corrosion-resistant, durable, and suitable for potable water

• Efficient spiral heat exchanger: 3.3 m² surface, high transfer capacity

• Ideal for heat pumps: optimised for low supply temperatures

• 50 mm PUR insulation: minimal standby losses and high efficiency

• Versatile connection options: easy integration into various systems

• Compact & space-saving design: less installation space required

Technical specifications (summary):

• Total volume: 500 litres

• Boiler tank: 300 litres

• Buffer tank: 200 litres

• Tank material: Duplex 2205 stainless steel

• Insulation: 50 mm PUR rigid foam

• Coil surface area: 3.3 m²

• Max. operating pressure (tank): 10 bar

• Max. operating pressure (coil): 16 bar

• Max. tank temperature: 95 °C

• Dimensions (H x Ø): 1800 x 650 mm

• Connections: G 1¼", G 1", sensor ports

Applications:

• Air-to-water and ground-source heat pumps

• Solar thermal systems

• Hybrid heating systems

• New-build homes, apartments, commercial buildings

• Hotels, sports facilities, agricultural and commercial installations