Bosch Greenstar 12i Service Manual download pdf (Page 67)

FAULT FINDING AND DIAGNOSIS

6 720 644 743b (2011/08)

67

7.2 BOILER FUNCTION

Fig. 124 Boiler function

NO

YES

MAINS

POWER

SUPPLY

ON

BOILER

DEMAND

Fan to

start

speed.

Pump ON.

IGNITION

SEQUENCE

(see detai )

BLUE

LIGHT

ON

BURNER

LIT?

GREEN

FLAME

LIGHT

ON

Stop spark

and gas.

Wait

10 seconds

5th

attempt?

LOCKOUT

10 second

stabi isation

period.

Fan

modu ation

to achieve

set

temperature

(40-82°C)

END OF

BOILER

DEMAND

Gas va ve

OFF

Pump run 3

minutes

Fan run 30

seconds

Over temperature shut-

down if water tempera-

ture is 5°C above set

va ue.

Gas va ve OFF.

Fan overrun

30 seconds

3 minute pump

over run

Spark

ignition

and gas

4 seconds

NO

YES

Room

thermostat and/or

mains

programmer ON

(or ink fitted at

ST10)

AND

Facia mounted

programmer (if

fitted) ON

AND

CH contro knob

ON

IGNITION SEQUENCE

6720644743-39.1Wo

1 2 ... 62 63 64 65 66 67 68 69 70 71 72

Comments to this Manuals

No comments