Oil Supply Vacuum Testing; Air Pressure Switch Connections; Appliance Reset; Appliance Reset Buttons - Bosch Worcester Greenstar Utility 32/50 Installation, Commissioning And Servicing Instruction Manual

8.4

Oil supply vacuum testing

A vacuum gauge can be attached to the oil pump vacuum test port [1]
and the appliance operated to check the vacuum readings. Oil pumps
can operate if readings are between plus 0.4 bar and minus 0.35 bar.
This means oil tanks can be 4 metres higher (to top of oil) or 3.5 metres
lower (if fitted with a de-aerator or two-pipe oil delivery system) than the
oil pump.
If vacuum is greater than minus 0.35 bar then you must also check that
the oil supply is not obstructed and that the oil supply pipe is correctly
sized.
Accessory 8-716-116-333-0 is available to assist in connecting a
vacuum gauge to the vacuum test port.
6
5
Fig. 62 Oil pump ports/connections
[1] Vacuum gauge port
[2] Pressure adjuster
[3] Bleed and pressure gauge port
[4] Return connection
[5] Inlet connection
[6] Auxiliary pressure gauge port
8.5

Air pressure switch connections

NOTICE: APS pressure sensing tubes
▶ Ensure that the pressure sensing tubes are not
kinked or trapped when working on the boiler.
▶ Kinked or trapped tubes will prevent the APS from
functioning correctly
Air pressure switch sensing tube connections:
▶ Ensure that the sensing tubes are connected
correctly, refer to figure 63.
3
Fig. 63
[1] Air Pressure Switch
[2] Air intake connection (front APS connection)
[3] Flue exhaust connection (rear APS connection, marked with a +)
Greenstar Utility ErP - 6 720 821 751 (2018/04)
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2
3
4
1
2
8.6

Appliance reset

8.6.1

Appliance reset buttons

Air pressure switch reset [1]
Flue system restriction or blockage will cause the air pressure switch to
trip bringing the appliance into a lockout state.
▶ Clear the restriction or blockage.
▶ Reset by pressing the protruding button [4] on the air pressure
switch [1].
Flue overheat reset button [2]
If the flue-gas temperature exceeds the cut-off set point the appliance
will lockout,
▶ When the flue has cooled down, reset by pressing the protruding
cross button, the button will click when a reset is possible.
Appliance overheat reset button [3]
If the appliance temperature exceeds the cut-off set point the appliance
will lockout,
▶ When the appliance has cooled down, reset by pressing the
protruding cross button, the button will click when a reset is
possible.
1
3
Fig. 64 Appliance reset button locations
8.6.2

Burner reset button

The burner is located in the lower third of the appliance, the burner reset
button will illuminate if the burner is in a lockout state.
▶ Reset the burner by pressing the illuminated button.
1
Fig. 65 Burner lockout indicator and reset button
Fault finding and diagrams
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6720821571-47.1Wo
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