Worcester C1 Installation And Servicing Instructions page 44

Fig. 1. System Diagram.
Expansion
vessel
Fixed
by-pass
CH
flow
4
The flow is limited within the appliance to give a hot water
delivery rate to a maximum of 10.0 (±15%) litres/minute (2.0 gallons/
minute).
Hot Water and Central Heating mode:
When a demand is made for heating by the system controls (i.e. a
programmer or room thermostat).
The pump will energise circulating primary water around the
heating system and the burner will light. The heat output from the
appliance in this mode has been factory set to maximum. The
appliance will operate as necessary to maintain the temperature of the
radiators at the level set by the adjustment of the Heating
Domestic Domestic CH
hot water cold return
supply supply
Automatic air
vent
Primary heat
exchanger
Circulating
pump
Domestic
water flow
switch
Relief valve
Relief valve
discharge
Temperature Control Knob.
(See Fig. 2.)
If the system no longer
requires heat to maintain the
desired room temperature, the
burner will extinguish. The
pump will continue to run for
a short period to dissipate the
residual heat from the
appliance and then switch off.
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.