CAWT-500L Fast Boiler Tank – 500-Litre Stainless Steel Horizontal Coil Boiler for Heat Pump Systems

The CAWT-500L Fast Boiler Tank is a powerful, high-quality and future-proof solution for modern heating systems where durability, reliability and hot water comfort are key. This 500-litre horizontal tank features an efficient spiral coil heat exchanger and is entirely made of Duplex 2205 stainless steel – a premium alloy known for its strength, corrosion resistance and thermal stability.

Specially designed for use with heat pumps and other renewable energy sources, this boiler ensures fast, efficient and stable hot water storage. Its indirect heating system with built-in spiral coil ensures maximum heat transfer, even at the lower flow temperatures typical of heat pump systems.

The tank is equipped with a high-quality 50 mm PUR rigid foam insulation layer, which minimises heat loss and ensures energy-efficient operation. Thanks to its horizontal design, the CAWT-500L is ideal for installation in technical spaces with limited ceiling height or where vertical placement is not feasible.

With its robust construction, multiple connection options and long service life, this boiler is the perfect choice for professional installations in residential buildings, apartments, commercial projects and agricultural setups.

✅ Key Benefits:

• 500-litre net volume – ideal for large hot water demand or as buffer tank

• Duplex 2205 stainless steel – corrosion-resistant, pressure-resistant, potable water safe

• Integrated spiral coil heat exchanger – high thermal transfer efficiency

• Designed for heat pumps – also suitable for solar thermal and hybrid systems

• Premium PUR insulation (50 mm) – extremely low standby losses

• Horizontal configuration – for technical rooms with limited height

• Multiple connection options (top/side) – easy to integrate into any system

• Long-lasting & reliable – resistant to condensation and thermal fluctuations

⚙️ Technical Summary:

• Gross volume: 500 litres

• Material (tank & coil): Duplex 2205 stainless steel

• Insulation: 50 mm PUR rigid foam

• Max. operating pressure (tank): 10 bar

• Max. operating pressure (coil): 16 bar

• Max. operating temperature (tank): 95 °C

• Coil surface area: 2.9 m²

• Heat exchanger output at 80/10/45°C: approx. 34.4 kW

• Dimensions (LxØ): ± 1975 x 650 mm

• Connections: various (G 1¼”, G 1”, sensor ports)

Applications:

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

• Solar thermal systems

• Hybrid heating installations

• Residential buildings (single homes, apartments, villas)

• Commercial properties (schools, offices, sports facilities)

• Agricultural and light industrial systems

The CAWT-500L Fast Boiler Tank from Coolmark is built for installers who demand top-level quality, performance and durability. Its combination of Duplex stainless steel, smart construction and high thermal transfer makes this boiler the reliable core of any sustainable hot water system.