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) 

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INSPECTION AND SERVICE

External oil filter:

Remove the paper element from the external 

oil filter and replace it. If the filter contains a
washable element, thoroughly clean in 
kerosene and reassemble into the filter.

Clean the boiler:

Manifold access:

Remove top cover by releasing the  

screws at each corner and lift free.

Release screws (E) to remove the flue 

manifold access cover (F) and clear any
debris.

Check the condensate route (G) is clear and

clean the condensate trap and pipework.

Check the flue system and clean if necessary.

Remove the baffle retainer (J) and baffles (H)

from the secondary heat exchanger.

Check and clean the secondary heat 

exchanger surfaces.

Pour 500ml of water into drain (G) to refill the 

condensate trap.

Clean the secondary heat exchanger baffles

(H) if necessary and refit correctly.

 Refit the baffle retainer (J).

Check the seal on the manifold access cover 

(F) and replace if necessary.

Refit the flue manifold access cover (F)

and secure with screws (E).

Combustion chamber:

Release the M10 retaining nuts and washers 

(B) and remove combustion chamber access
door (A).

Check the fibreglass rope seal on the

combustion chamber access door (A) and
replace if necessary.

Remove and check the baffle retainer (D).

Remove the baffles (C), clean and check the

condition of the baffles and the acoustic
insulation. Replace any baffles or insulation
pads considered to be badly corroded/degraded.

Thoroughly clean all of the heat exchanger 

surfaces using a suitable brush and clear all 
loose debris from the combustion chamber.

Check the condition of the combustion 

chamber access door insulation. If the
insulation is damaged the door assembly 
must be replaced.

Refit the items in reverse order ensure the 

baffles (C) and baffle retainers (D) are
correctly fitted for the boiler output as shown
in the plan view opposite.

Refit combustion access door (A).

Secure with nuts and washers (B) and 

tighten until the door is firmly secured, do not
over tighten the nuts.

Fire valve:

Check that the oil supply pipe has a fire valve

fitted at least 1m away from the appliance 
with the fire valve sensor located within the
appliance case. A fire valve sensor clip (K) is

provided for this purpose.

A

B

D

C

K

H

G

Plan sectional view

D

C

Plan sectional view

E

F

J

H

G

J