Worcester CDi Combi N.G Service Booklet page 21

1.E PUMP SWITCH MODE
The choice of settings is as follows:
• Control Mode 1
For heating equipment without a control unit.
The pump is controlled by the central heating flow
temperature control.
• Control Mode 2 (factory setting)
For heating systems with room thermostat.
The central heating flow temperature control controls
only the gas, the pump is not affected. The room
thermostat controls both the gas and the pump.
The pump and fan have an over-run time of between
15 s and 3 min.
• Control Mode 3
Not applicable
2.B MAX. FLOW TEMPERATURE
The maximum CH flow temperature can be set to
between 35 °C and 88 °C (factory setting). Even if the
CH flow temperature control is set higher, the setting
entered for 2.b (Max. flow temperature) is not
exceeded.
2.C AIR PURGE MODE
The first time the appliance is switched on, a once-only
venting function is activated. The heating pump then
switches on and off at intervals. This sequence lasts
about 8 minutes.
The 2-digit display shows
flow temperature.
The automatic vent will open during venting and then
close once the venting sequence is complete.
The venting function can be activated
manually after servicing.
• If the venting function is set to "On" (with automatic
deactivation), the function is set to "Off" once the
sequence has been completed
2.F OPERATING MODE
There are 3 operating modes to choose from.
• Normal mode: the appliance operates according to
the commands received from the programmer. The
display shows 0.
• Minimum mode: the appliance runs constantly at
minimum output.
The display shows 1. The 2-digit display alternates
between the CH flow temperature and
15 min the minimal mode changes to normal mode.
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in alternation with the CH
. After
• Maximum mode: the appliance runs constantly at
maximum output.
The display shows 2. The 2-digit display alternates
between the CH flow temperature and
15 min the maximal mode changes to normal mode.
3.B ANTI-CYCLE TIME
The anti-cycle time is factory set to 3 minutes.
The shortest possible anti-cycle time is 1 minute
(recommended for single-pipe and hot-air heating
systems).
If the setting 0 is entered, the anti-cycle time is inactive.
B Enter the anti-cycle time on the commissioning record
enclosed with the appliance.
3.C ANTI-CYCLE FLOW TEMPERATURE DIFFERENTIAL
The switching difference is the permissible differential
from the specified CH flow temperature. It can be set in
increments of 1 K. The adjustment range is 0 to 30 K (is
factory set to 10 K). The minimum CH flow temperature
is 35 °C.
Note: 1K = ^ 1 °C.
B The switching difference setting should be entered on
the commissioning record supplied with the
appliance.
3.E CYCLE TIME (HOT WATER) (COMBI ONLY)
The appliance is supplied with the pre-heat cycle time
set to 20 minutes.
After pre-heating or DHW demand, this function will
stipulate the period of time before the next permissible
pre-heat. This will prevent excessive pre-heat cycling.
3.F BURNER OFF AFTER DHW DEMAND (HOT WATER)
(COMBI ONLY)
The appliance is supplied with the hot water duration
set to 1 minute.
The "hot water duration" time specifies how long, after
hot water has been drawn, that the heating mode
remains disabled.
. After
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