Technical data

46
16. Operational Flow Diagrams
Frost thermostat and CH
control knob ON
OR
Room thermostat ON
(or link)
CH programme ON
(or link)
CH temperature control
ON
(NO HW demand)
(NO TANK demand)
230V
mains
supply to the
boiler.
Green
power
light ON.
CENTRAL
HEATING
DEMAND
230V
mains
supply to the
boiler .
Modulate
heat input to
maintain set
point set by
user
control
(50-82°C).
CH light ON.
Pump ON.
Diverter valve
ON.
Ignition
Sequence
at minimum
heat input.
DEMAND
END
Minimum
heat input for
20 seconds
then ramp up
over next
minute.
CENTRAL HEATING MODE
AND
AND
DOMESTIC HOT WATER MODE
Green
power
light ON.
Tank 7°C
below
set point.
CH
temperature
5°C above set
point.
Gas valve OFF.
CH light ON.
Pump ON.
Diverter valve
ON.
3 minute wait
CH
temperature
4°C below
set point.
Pump and
diverter
valve
energised for
3 minutes.
AND
HW
temperature
control ON.
HW flow above
2.7 l/min.
AND
HW programmer ON
(or link)
HW flow above 9 l/min &
HW temperature lower
than set point
OR
HW flow below 9 l/min &
HW temperature
4°C below
set point.
HW
light ON.
Pump ON.
AND
Modulate heat
input to
maintain
temperature
set by user
control
( 55-75°).
Ignition
sequence at
minimum heat
input.
Flow
less than
2 l/min.
Modulate heat
input if the
flow is above 9
l/min.
Minimum heat
input for 30
seconds if the
flow is below
9 l/min.
65% heat
input if
primary
temperature
above
84°C.
DHW clock OFF
OR
DHW temperature 6C
above set point
OR
DHW flow below 3.9
litres & DHW
temperature
above set point.
Gas valve
OFF.
TANK
MODE
OVERRUN
MODE
Pump continue for
3 seconds.
Pump pulse for 3 seconds if
primary temperature is
above 82°C.
Tank 7°C
above
set point.