Bosch 12/18 User Manual

STARTING THE APPLIANCE

INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32

8 716 113 389b (09/07) 

31

C

O

MMI

S

S

IO

N

IN

G

F

H

G

Return

Flow

A

B

C

A

B

C

A -  Bleed & pressure gauge port

B -  Pressure adjustment

C -  Vacuum gauge port

D -  Retaining screws - cover

D

D

C

B

A

D

GREENSTAR HEATSLAVE EXTERNAL 

flue

reset

boiler

reset

lockout

on

service

(Under control box)

(On top of burner control box)

E - Lockout indicator

STARTING THE APPLIANCE

IMPORTANT: Never run the appliance when
the appliance/system is unpressurised
(sealed systems) or empty.

1

Check the oil supply is correctly fitted and

in good working order before turning on
the oil supply valves to the boiler.

Turn on the main oil supply valve at the tank

and draw off at least 2

1

/

2

litres of oil until a 

steady flow of clear uncontaminated oil can
be seen as follows:

•  The oil supply to the boiler should be

primed before the burner is operated to

avoid unnecessary pump wear.

•  The use of an oil suction pump will prime

and flush through any oil supply set up 

simply and easily, alternatively the 

following procedures can be used.

Single pipe gravity feed systems:

Disconnect the flexible oil hose and open

the isolating valve to discharge the oil into a
suitable container.

If a top entry tank has been used the 

pipework will need to be primed before the
oil will discharge under gravity.

When completed, close the isolating valve,

reconnect the flexible oil hose.

Double pipe sub-gravity feed systems 

and single pipe suction lift with de-aerator:

To prime a de-aerator, disconnect the      

flexible oil inlet hose (F) from the isolation valve

and place in a container of kerosene (G). 
Connect a spare flexible oil hose (H), to
discharge into container (G). Open the
isolating valve, turn on the power to the boiler 
and set the programmer to ON. Prime the 
de-aerator until there is a steady flow of oil into
container (G). Turn off the boiler then 

reconnect the flexible oil inlet hose (F).

Turn on the boiler, the oil level in the 

de-aerator will drop as the oil is used until 
the oil is drawn from the tank. If the 
de-aerator empties and the burner locks out 
before the oil is drawn from the tank, prime 
the de-aerator again.

Open the isolating valve and the oil pump

bleed valve (A) to discharge into a suitable
container once the boiler is started up.

Switch on the electricity supply to the boiler.

Set the programmer to ON for CH and DHW.

Turn on the boiler CH control thermostat.

Allow the burner to run through to lockout

indicated by the illumination of the lockout

indicator (E).

Wait 2 minutes then press the lockout reset

button (D).

Repeat the procedure at least 3 times or until a 

steady stream of oil, without air, runs from the 
bleed port, then relock the bleed port (A).

Switch off the boiler.

Remove the oil pump filter, clean with 

kerosene and refit.

The internal filter is accessed by removing 
the oil pump cover on the Danfoss BFP 11 

L3, Suntec AS47C and Riello RDB.

Safely dispose of the container/discharge.