Domestic hot water system

摘要

The hot water system has a boiler (1) with a flow and return circuit. It has an additional secondary circuit running from the boiler flow with a fitted mixing valve, for the purpose of temp. control and incorporating a radiator. A thermostat is fitted on a common flow to both circuits and control pipes lead to it, to the circulation pump, to a mixing valve and to an outside thermostat. The control (4) on the temp. outside falling below a predetermined level periodically allows circulation to proceed.