The DuoWave range of mains pressure hot water cylinders were developed to meet the growing demand for systems that combine a renewable heat source with a standard oil, gas or electric boiler.They are particularly suitable for use with solar hot water systems like Grant Solar Thermal. When correctly installed, this arrangement can significantly reduce the dependence on traditional fossil fuels resulting in lower energy bills. Sizes range from 170 litres to 400 litres, comprising five direct and five indirect models which can meet the needs of even the largest of domestic properties.