Bosch Worcester 400 - Manual (Page 4)

Hot Water and Central Heating Mode:
The appliance will supply heat to the central heating system as
required. A demand for hot water at a tap or shower will override the
central heating function for the period of the domestic hot water
demand.
When domestic hot water is no longer required the burner and
pump will continue to operate until the heatbank is back to the
required temperature.
The appliance will then return to the central heating state and
its normal mode of operation.
Similarly the hot water is occasionally diverted from the central
heating system into the heatbank to maintain the stored primary hot
water temperature.
NOTE: If in doubt about the use of the controls ask your
installer to assist you.
Central Heating Mode:
When a demand is made for heating by the system controls (i.e.
a programmer or room thermostat).
The water diverter valve will open, the pump will energise circu-
lating primary water around the heating system and the burner will
light. The appliance will operate as necessary to maintain the temper-
ature of the radiators at the level set by the adjustment of the Heating
Temperature Control. (See Fig. 2.)
If the system no longer requires heat to maintain the desired
room temperature, the burner will extinguish. The pump will contin-
ue to run for a short period to
dissipate the residual heat from
the appliance and then switch
off.
4
Fig. 1. System Diagram of Highflow 400 Electronic Series.
Primary
Water
circulation
Water
diverter
valve
From
radiators Mains
cold in
Flow tur-
bine
Domestic hot
water out
Expansion
vessel
Slot in
front cover.
(O.F. only)
Pilot obser-
vation win-
dow.
To
radiators
Circulating
pump
Heat
exchanger
Heatbank
Burner
Boiler