Replacement Parts; Draining The Appliance - Worcester GR8700iW 35 C Installation And Maintenance Instructions Manual

Maximum rated output
Gas type CO O
2 2
Natural gas 9.5 % 4.0 % <250ppm 8.6 %
± 0.4
Liquid 10.8 % 4.6 % <250ppm 10.2 %
propane (LPG) ± 0.4
Table 23 CO and O contents
2 2
▶ Measure the CO content.
The CO content must be < 250 ppm.
▶ Set the minimum rated output.
▶ Measure the CO or O content.
2 2
▶ Remove the seal from the adjusting screw of the air/gas ratio control
valve (only air/gas ratio control valve is shown in the below Fig. 97)
and set the CO or O content for minimum rated output.
2 2
4 mm
T40
Fig. 97 Setting the CO or O content (above: SIT valve, below:
2 2
Honeywell valve)
▶ Re-check settings at maximum and minimum rated output and re-
adjust if required.
▶ Seal the air/gas ratio control valve.
▶ Seal the adjustable venturi.
▶ Exit the chimney sweep mode.
▶ Enter the CO contents in the servicing record (Chapter 12.8,
2
page 77).
▶ Remove the flue gas probe from the flue gas test port and refit the
plug.
Greenstar 8000 Style – 6720883864 (2019/02)
Minimum rated output
CO CO O CO
2 2
5.5 % <75ppm
± 0.4
5.5 % <75ppm
± 0.4
0010024762-001 0010024762-001
9

Replacement parts

WARNING:
Mains supplies - Isolate the appliance
▶ Turn off the gas supply and isolate the mains electrical supply before
starting any work and observe all relevant safety precautions.
▶ Drain the appliance/system where necessary and protect any
electrical equipment from water ingress during component
replacement.
WARNING:
Component replacement:
▶ Replace the burner housing gasket and the Flueway sump seal when
re-assembling the heat exchanger. Do not reassembly the heat
exchanger and Flueway until new gaskets and seals are available.
▶ After replacement of a gas related component, where a gasket or seal
has been disturbed or replaced, check for gas tightness using a gas
sniffer/analyser.
▶ On re-assembly check all affected seals for cracks, hardness and
deterioration.
 If damaged or in any doubt the seal must be replaced.
▶ Also after re-assembly, carry out the following checks:
 Fan pressure.
 Flue gas analysis.
Only use Worcester, Bosch Group original spare parts with this
appliance. Non Worcester, Bosch Group original spare parts will
invalidate the guarantee (if applicable) and any warranty.
▶ A comprehensive list of appliance spares can be found on the website
www.worcester-bosch.co.uk/spares
9.1

Draining the appliance

NOTICE:
Risk of water damage to appliance or property!
Damage from disconnecting water pathways which may have retained
some water.
▶ Take care after draining the appliance to protect equipment/property
from residual water content within components.
Many of the tasks in this section require that the appliance be isolated
and drained. This will be indicated in the manual if required.
▶ The boiler drain is already connected to the condensate trap for ease
of draining.
-or-
▶ Connect a suitable hose firmly to the drain point and run the hose
outside to a suitable point or container.
▶ Turn the drain valve a ¼ turn anti-clockwise to open the drain. Turn
the valve firmly clockwise to close.
Replacement parts
63