Baxi BOSTON 40 OF, Инструкции по установке и обслуживанию

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a) The sizes of flow and return pipes from the boiler should be determined by normal methods
according to the requirements of the system. Normally the pump should be set to give a 11°C (52
°F) drop across the system with the gas rate of the boiler adjusted to the output required.
b) The open vent pipe must be a minimum of 22mm and must rise continuously to above the feed
tank. The flow pipe from the boiler may form part of the open vent. No part of the open vent should
contain a valve.
c) In a fully pumped system the cold feed pipe (15mm) may be connected to the flow pipe, 6 ins
away from the vent pipe, but there must always be a cold water path to the boilers return
connection.
DOMESTIC HOT WATER
An indirect cylinder must be used. If a self priming indirect type is employed it must be of adequate
size and applied strictly in accordance with the cylinder manufacturer's instructions.
FUEL ECONOMY
Better fuel economy is achieved by exercising control of the boiler by means of a room thermostat
and or a cylinder thermostat as appropriate. Examples of different control systems are given below
along with the appropriate wiring diagrams.
ALLOWING THE BOILER TO CYCLE ON THE BOILER THERMOSTAT DOES NOT PRODUCE
THE BEST RESULTS. SIMILARLY FOR ECONOMY AND BOILER PERFORMANCE THE
SYSTEM SHOULD BE DESIGNED SO THAT GRAVITY CIRCULATION IN THE HEATING
CIRCUIT DOES NOT TAKE PLACE WHEN THE PUMP IS NOT RUNNING.
Control Systems
FULLY PUMPED SYSTEMS
One Zone Valve ( Fig. A )
Zone valve with auxiliary switch fitted at point V. A cylinder thermostat and a room thermostat are
used to control both the pump and the boiler. The room thermostat also controls the zone valve to
stop water circulation in the heating system.
Two Zone Valves ( Fig. C )
Zone valves are fitted at points V and U to stop water circulation to the heating system and the
cylinder. The valves are controlled by a room thermostat and a cylinder thermostat respectively,
each of which also controls the boiler and the pump.
Diverter Valve ( Fig. D )
A diverter valve is inserted at point W to direct water circulation to either the cylinder or the heating
system. The valve along with the pump and the boiler is controlled by a cylinder thermostat and a
room thermostat.
GRAVITY D.H.W. SYSTEMS
Sundial Control ( Fig. B )
Both the boiler and the pump are controlled by a cylinder thermostat and a room thermostat. The
room thermostat overrides the cylinder thermostat when heating is called for.