<p>The central heating system has a single control which operates the boiler only if at least one of the valves controlling each room is open. The heating system comprises a boiler (1), a circulation pump (3) and heat exchangers (8) in each room (22). A distributor (5) feeds each room circuit through on/off valves (6). The central control unit (14) registers the boiler output temperature by means of a sensor (4), and the condition of the valves (6), and switches on the boiler and/or the pump accordingly.</p>
