Our SST Buffer Tanks are proudly presented under the name "Fast". This designation not only signifies speed but also symbolizes reliability and trust. Read more.
The CDWT-250L Fast Boiler & Buffer Tank Combination by Coolmark is a powerful, compact and energy-efficient solution for modern heat pump systems. This unit combines a 190-litre boiler tank and a 60-litre buffer tank in one robust housing made of Duplex 2205 stainless steel. It’s ideal for installations where space is limited, but performance cannot be compromised.
Both tanks are made from Duplex 2205 stainless steel, offering excellent corrosion resistance, long service life and high-pressure durability. This 2-in-1 unit is perfect for residential and light commercial applications.
The integrated spiral coil heat exchanger features a surface area of 1.7 m² and is optimised for low-temperature sources like air-to-water heat pumps. This allows for fast and efficient domestic hot water heating, even at low flow temperatures.
The entire unit is insulated with 50 mm high-density PUR rigid foam, minimizing heat loss and contributing to an energy-saving heating system. Thanks to its compact size and smart connection options, this boiler fits easily in smaller technical rooms.
Key Benefits:
2-in-1 system: 190L boiler + 60L buffer tank in a single unit
Duplex 2205 stainless steel: corrosion-resistant, durable and potable water approved
Spiral heat exchanger (1.7 m²): fast thermal transfer, optimised for heat pumps
50 mm PUR insulation: excellent thermal retention, minimal standby losses
Compact and efficient: perfect for homes and spaces with limited room
Multiple connection options: easy integration into new or existing systems
Technical Specifications (summary):
Total volume: 250 litres
Boiler tank: 190 litres
Buffer tank: 60 litres
Material: Duplex 2205 stainless steel
Insulation: 50 mm PUR rigid foam
Coil surface: 1.7 m²
Heat exchanger output at 80/10/45 °C: approx. 18.7 kW
Max. operating pressure (tank): 10 bar
Max. operating pressure (coil): 16 bar
Max. tank temperature: 95 °C
Dimensions (H x Ø): 1350 x 650 mm
Connections: G 1¼", G 1", sensor ports
Applications:
Air-to-water and ground-source heat pumps
Solar thermal and hybrid heating systems
Residential buildings, apartments, commercial properties
Renovation projects, small technical rooms
Light commercial and agricultural systems
The CDWT-250L is the ideal solution for those seeking a durable, compact, and high-performing boiler for heat pump systems. Built with premium materials, an efficient coil, and smart design, this unit is future-ready.
