Worcester Highflow 400 RSF Installation And Servicing Instructions page 4

With the system at the temperature set by the Temperature
Control Knob,on the facia, the burner will cycle to maintain
output to the system.
If the system no longer requires output to maintain the desired
room temperature, the burner will extinguish. The pump will
continue to run for about five minutes to dissipate the residual
heat from the appliance and then switch off.
When the primary water has cooled sufficiently below the
temperature set by the Temperature Control Knob, the burner
will light, pump will energise and process repeated.
Fig. 1. Appliance water flow diagram.
Return Valve
Flow Valve
Water Manifold
(Top Section)
Manual Air Vent
Pressure Relief
Valve
1
By-Pass
Adjuster
Water to Water
Heat Exchanger
Water Manifold
(Bottom Section)
Water Diverter
Valve
Open Vent
Position
Drain
(Secondary Water)
Circulating
Pump
1
C.H. Thermostat
2
Safety Temperature Limiter
3
H.W. Thermostat
Central
Central
Domestic
Heating
Heating Hot Water
Return
5
Out
Flow
ZAGAS041
ZAGAS043
ZAGAS042
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 hot water
demand.
When 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 return to the central heating state and its
normal mode of operation.
Mains Cold
Automatic Air
Water In
Flow Switch
Water Filter
4
Heatbank Overheat Thermostat
5
H.W. Limit High Thermostat
4
Vent
Water Flow
Regulator
Appliance
Cabinet
Gas to Water
Heat Exchanger
2
Boiler
Sealed System
Expansion
Vessel
3
4
Heat-Bank
Capacity 60 Litres
Drain
(Primary Water)
ZAGAS044
ZAMAJ 223