Fan Pressure Test - Worcester GREENSTAR 24i Junior Installation, Commissioning And Servicing Instructions

SERVICE AND SPARES
Fig. 76 Flue integrity test
6.4

FAN PRESSURE TEST

This test is to determine if the heat cell requires
cleaning/attention.
SETTING THE BOILER TO MAXIMUM
1. Press and HOLD service button for more than 10 seconds
2. Set the Central Heating temperature to maximum.
– The service button will illuminate continually and the blue power
indicator will pulse 5 times.
– The boiler will stay in this mode for 15 minutes unless the service
button is pressed again.
1.
2.
Fig. 77 Set boiler to maximum
When running in the service mode, the boiler will operate
both the Central Heating and DHW circuits. This is to
allow sufficient time for setting procedure.
It will be necessary to run water through the DHW circuit
to ensure that the boiler will not cycle on low heating
demands.
36
FAN PRESSURE
Fig. 78 Fan pressure test point
▶ Remove the cover and connect a digital manometer to the fan
pressure test point.
▶ After measurement replace test point cover.
▶ The pressure will read negative, refer to the chart in figure 79.
NOTICE:
The boiler must be run at maximum output for Fan
Pressure test and the Flue Gas analysis.
Clean the Heat Ex.
NG Boilers
28 i Junior:
- 3.1
24 i Junior:
0 -1 -2 -3
LPG Boilers
28 i Junior:
24 i Junior: - 3.6
0 -1 -2 -3
Fig. 79 Fan pressure readings
If the boiler fails the fan pressure test then before adjusting the air/gas
ratio, try the following:
▶ Check the syphon is not blocked.
1. Remove the screws securing the sump cover.
2. Remove the sump cover.
3. Clean the sump and heat exchanger with a suitable brush
▶ Check the exhaust path and flue for restriction.
▶ Re-check the Fan Pressure readings
Heat Ex. ok
- 3.9
-4 -5 -6 -7 -8
mbar
- 4.6
-4 -5 -6 -7 -8
mbar
6 720 802 047 (2013/05)