Bosch Appliances 24i junior Ignition Sequence, Central Heating Function, Fault Finding Diagrams

INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR 24 i junior/28 i junior 8 716 107 336b (11/05)

POWER SWITCH ON

BLUE LIGHT ON

	Gas valve OFF.
3 minute wait	Fan overrun
	30 seconds

Room
thermostat and/or
mains
programmer ON
(or link fitted at			Fan to		IGNITION	GREEN
ST10)	CENTRAL
						FLAME
AND			start		SEQUENCE
	HEATING					LIGHT
Facia mounted	DEMAND		speed.		(see detail)
						ON
programmer (if fit-
ted) ON
AND		Diverter valve
CH control knob
ON		in CH position		IGNITION SEQUENCE
		Pump ON.

Over temperature shut- down if water tempera- ture is 5°C above set value.

	Fan (& gas)
10 second	modulation	END OF
	to achieve
stabilisation		BOILER
	set
period.		DEMAND
	temperature
	(40-82°C)

CENTRAL HEATING FUNCTION

56

Spark

ignition

4 seconds

NO

	YES	5th
LOCKOUT
		attempt?

FAULT FINDING

& DIAGRAMS

YES

BURNER

LIT?

NO

Stop spark.

Wait

10 seconds

Gas valve

OFF

Pump run 3

minutes

Fan run 30

seconds

CENTRAL HEATING FUNCTION