There are three Vision Plus S (heat only) models in the range: 20, 25 and 30kW. These system boilers can provide central heating only or be match with Vokèra AquaFlow unvented cylinders to provide domestic hot water storage. A wide modulation ratio ensures flexibility and efficiency and, thanks to the Modbus protocol, the entire Vision Plus range is designed to be ‘hybrid ready’ for integration into low carbon heating system designs. For further flexibility, all system models boast a built-in relay, which allows for easy integration with zone valves.