Gas fired central heating and hot water system - times changes in reference signal levels to ensure efficient fuel use during periods of low demand

摘要

Gas flows via a valve (32) to the burner (34) which heats the primary water as it flows through a heat exchanger (3). The water is pumped (19) through the heat exchanger to a three-way valve (14). The valve delivers differing flows to another heat exchanger in the hot water heater (8), and to radiators (9). The used water is recirculated by the pump. A combined clock and control unit (13), receives signals from temp. sensors in the pump outlet pipe (20) in the primary hot water delivery pipe (5), in the secondary hot water boiler (22), in the volume heated by the radiators (11) and in the open air (29). The controller operates the gas inlet valve (32) via a solenoid (31), and the motors (15,18) for the three-way valve and the pump. Adjustable temp. reference levels (24,25) are used to control the water temps. at low demand times of the day.