Technical data

31
Burner light
ON.
Pump ON.
Fan to
maximum
speed.
3 min
wait.
Green
light
ON.
Room thermostat
and/or mains
programmer (or
link) ON
AND
Electronic facia
programmer
(if fitted) ON
AND
CH control knob
ON.
CENTRAL HEATING FUNCTION
Over temperature
shut-down if water
temperature is 5°C
above set value.
Gas valve shuts.
Red light remains ON.
Pump remains ON.
Mains
switch
ON.
CH
demand.
Air
pressure
switch
check.
Fan to start
speed.
Air pressure
switch closes.
Gas valve opens.
Burner
stabilises at
maximum
input for
10 secs.
Minimum
heat input
for 1.5 min.
Boiler
operates to
match
system load
and CH
control
setting.
Ignition spark for
5 sec.
Burner lights.
Red light ON.
Ignition sequence
Yes
No
Fan runs to purge
gas from burner.
Repeats 5 times
before lock-out.
* NOTE: A control sequence checks that the condinsate siphon is full.
Fan speed
reduces
over 15
sec.
Siphon
check
(Default)
*
Maximum
heat
input for
15 min.
Yes
No
CH demand
satisfied.
Gas valve
closes.
Red light
out.
Fan runs for
upto 3 min.
Pump runs for
3 min.