Worcester 29CDi Classic

FAULT FINDING & DIAGNOSIS
6 720 815 725 (2015/05) 55
7.3 CENTRAL HEATING FUNCTION
POWER
SWITCH
ON
BLUE
LIGHT
ON
GREEN
FLAME
LIGHT
ON
END OF
BOILER
DEMAND
CENTRAL
HEATING
DEMAND
LOCKOUT
BURNER
LIT?
IGNITION SEQUENCE
IGNITION
SEQUENCE
(see details)
YES
YES
NO
NO
Burner restarts after
anticycle time (3 minutes)
has expired and water
temperature is
< CH setpoint by 10K
Diverter Value
in CH position
pump ON.
Gas value OFF.
Fan overrun
30 seconds
Over temperature
shut-down if water
temperature exceeds
set value
(CH setpoint).
90 seconds
stabilisation
period.
Gas value
OFF
Pump run 3
minutes
Fan run 30
seconds.
Fan (& gas)
modulation
to achieve
set
temperature
(35-88
0
C)
Fan to
start
speed.
Spark
ignition
4 seconds
5th
attempt?
Stop spark.
wait
10 seconds
Room
thermostst and/or
mains
programmer ON
(or link fitted at
ST10)
AND
Facia mounted
programmer (if
fitted) ON
AND
CH control knob
ON
6720647361-59.2Wo