Space heating installation control - uses room thermostats overridden by boiler output temp. sensor in colder weather

摘要

The process is governed by a comparator (9) controlling the furnace (1) as a function of the difference between the temps. displayed at a set point (8) and measured by a sensor (7) in the water return pipe. The set point (8) temp. is governed by a regulator (10) as a function of the difference between a second set point (11) and the ambient temps. obtd. at room thermostats (12). Overriding control is exercised by another thermostat (14) in the boiler output pipe if one of the contacts (15, 16) mounted on either side of an exterior wall (17) is closed.