Control for central heating system - has thermostatically controlled throttling valve to mix boiler flow and return

摘要

The heating system has a boiler (1) supplying space heaters (3). There is a pump (2) in the flow which has a variable volume capacity. There is a connection (8) between the return (6) from the space heaters (3) and the flow between the boiler and the pump. There is a throttling valve (9) in this connection (8), and a non-return valve (10) in the flow (4) between the boiler and the junction with the connection (8) from the return. The throttling valve is controlled directly by a thermostat which may respond either to outdoor temperature or to room temperature. It is a capillary or bimetal type which operates the valve directly without an electric positioning motor. The valve has a linear characteristic.