Indirectly fired Fast boiler and buffer tank in 1 (housing) CDWT-215L Duplex 2205 Boiler tank 150 liters, Buffer tank 65 liters, with coil (spiral) Heat pump boiler

CDWT-215L – Fast Boiler Tank & Buffer Tank in one housing – 215 Liter (150L + 65L), Duplex 2205 Stainless Steel, with Spiral Heat Exchanger for Heat Pump

The Coolmark CDWT-215L Fast Boiler and Buffer Tank is a compact 2-in-1 solution for installations where energy efficiency, space savings, and high performance are essential. With a 150-liter capacity for domestic hot water and a 65-liter buffer tank for low-temperature heating, this unit is perfectly suited for applications with heat pumps, solar energy, or hybrid heating systems .

Both tanks are individually integrated into a single, robust housing made of Duplex 2205 stainless steel – a high-quality alloy known for its excellent corrosion resistance , pressure resistance, and hygienic properties. This choice of material makes the CDWT-215L not only durable and low-maintenance, but also suitable for drinking water use and applications in humid or aggressive environments.

The 1.7 m² spiral heat exchanger (coil) is fully integrated into the boiler tank and ensures powerful and efficient heat transfer, even at low supply temperatures. This makes this unit ideal for use with air-to-water heat pumps or systems with low temperature regimes.

The tank is fully insulated with 50 mm of rigid PUR foam with a very low thermal conductivity coefficient. This minimizes downtime losses and maximizes the energy efficiency of the entire heating system. Thanks to its compact design and smart connections, the CDWT-215L is easy to integrate into small utility rooms, such as built-in cupboards, storage spaces, or under stairs.

Key Benefits:

• Compact 2-in-1 system: 150L boiler + 65L buffer tank in one housing

• Duplex 2205 stainless steel: pressure-resistant, corrosion-resistant, suitable for drinking water

• 1.7 m² spiral heat exchanger: high transfer efficiency, optimized for heat pumps

• 50 mm PUR insulation: excellent thermal insulation, minimal heat loss

• Space-saving design: fits in small technical rooms or renovation projects

• Easy installation: flexible connections and sensor inputs for control technology

• Energy-efficient and low-maintenance: suitable for sustainable applications

Technical specifications (summary):

• Total volume: 215 liters

• Boiler tank: 150 liters

• Buffer tank: 65 liters

• Tank material: Duplex 2205 stainless steel

• Insulation: 50 mm PUR hard foam

• Spiral surface: 1.7 m²

• Heat exchanger capacity at 80/10/45 °C: approx. 18.7 kW

• Max. working pressure tank: 10 bar

• Max. working pressure spiral: 16 bar

• Max. tank temperature: 95 °C

• Dimensions (h x Ø): 1280 x 650 mm

• Connections: G 1¼", G 1", temperature sensor inputs

Applications:

• Air/water and ground/water heat pumps

• Solar boiler systems

• Hybrid heating systems (e.g. central heating + heat pump)

• New construction, renovation, tiny houses and apartments

• Technical rooms with limited installation space

• Small utility projects, holiday homes, agricultural use

The CDWT-215L is designed for installers and end users seeking a sustainable, compact, and intelligent boiler solution with high performance and maximum flexibility. The combination of advanced materials, sophisticated design, and efficient heat transfer makes this unit an absolute asset to any future-oriented energy system.