Bosch 12/18 User Manual

INSPECTION AND SERVICE

INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 113 389b (09/07) 

38

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A

RES

1 Clean the Burner:

Remove the air intake cover (H) and clear 

any debris from the air intake and air damper.

Disassemble the burner to allow access to 

the fan impeller.

Check the condition of the gaskets between 

these parts and replace if necessary.

Note the position of the air damper 

adjustment and check the air damper moves
freely.

Clean both sides of the fan impeller and 

remove any debris from the burner housing.

Check that the impeller rotates freely.

 Reassemble the components.

Remove the combustion head (K) and

thoroughly clean any deposits.

Remove the nozzle (E).

2  12/18 & 18/25 Inspection of Mechanical

Shut-off Valve:

 Fasten an M5 screw, with a minimum length

of 30mm, into the threaded hole (L) and pull
the screw to withdraw the check valve (M).

Check that the nozzle holder (N) is clear of 

any debris and clean if necessary.

Check that the three holes in the check valve

(M) are clear of any debris. Check the 

condition of the 'O' ring (O). Discard the
check valve if the holes cannot be cleared, if 
the unit is defective or if the 'O' ring is 
damaged and replace with a new one.

Refit the check valve.

25/32

Check the nozzle holder is clear of any debris 

and clean if neccessary.

12/18, 18/25 & 25/32

Fit a new oil atomising nozzle (E).
DO NOT dismantle the nozzle and DO NOT
clean the nozzle tip.

Check the electrodes (F) and reset if 

necessary as shown opposite.

Refit the combustion head. Check that the 

nozzle (E) lies centrally in the combustion
head and the head settings are as shown.
Ensure that the photocell is lined up with the
sight hole.

 Withdraw the photocell (P) from its housing

and wipe clean.

 Remove the oil pump internal filter, clean in 

kerosene and reassemble.

The internal filter is accessed by removing
screws (A) and the oil pump cover (B) on the
Danfoss BFP 11 L3, Suntec AS47C and Riello
RDB.

Replace the standard flexible oil hose/s at

every annual service to prevent the
possibility of leakage due to ageing.

Reassemble the burner components.

Check the sponge O-ring seal located 

around the combustion head and replace if 
necessary. 
This seal must be in good condition since
failure will cause flue gases to escape into
the cabinet.

INSPECTION AND SERVICE

A

B

A - Retaining screws - cover

B - Cover - oil pump

H

P

D

5mm

Electrode gap
2.5 - 3.0mm

7.5mm

F

E

5mm

K

L

N

M

O

A

B

5mm

Electrode gap 4mm

F

E

K

5mm

H

P

D

A

B