Replacing The 3-Way Valve; Replacing The Plate Heat Exchanger; Following Inspection/Maintenance; Fault Finding And Diagnosis - Worcester GR8700iW 35 C Installation And Maintenance Instructions Manual

Fault finding and diagnosis

9.8

Replacing the 3-way valve

▶ Remove the screws.
▶ Pull out the 3-way valve.
▶ Press the cable retaining clip.
▶ Unplug the plug.
Fig. 105 Removing the 3-way valve
9.9

Replacing the plate heat exchanger

▶ Check the strainer in the cold water pipe for contamination
( Chapter 9.6, page 65).
-or-
▶ Remove the plate heat exchanger and replace.
1. Remove the screws.
2. Remove the plate heat exchanger.
2.
1.
Fig. 106 Removing the plate heat exchanger
▶ Install the new plate heat exchanger in reverse order.
▶ Make sure that the label "bottom" is facing downwards.
9.10

Following inspection/maintenance

▶ Re-tighten all the threaded connections that have been released.
▶ Restart the appliance.
▶ Check tightness of all joints.
▶ Check the gas/air ratio.
▶ Fit the combustion casing, side-, top panels and front cover.
66
10
This fault finding information is for guidance only. Worcester cannot be
held responsible for costs incurred by persons not deemed to be
competent.
This fault finding system assumes that the appliance has been operating
normally until the time of failure (i.e. not a first time installation error).
Basic checks
• Ensure that there is 230V power supply and the polarity is correct to
the appliance.
• Ensure that the appliance settings and functionality is correct.
• Ensure the CH/DHW programmer/timer is functioning.
• Ensure the room thermostat is functioning.
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• Ensure the cylinder thermostat (if fitted) is functioning.
• Ensure the cold water mains is turned on?
• Ensure the primary system has adequate pressure/system content
for the system type.
• Ensure there is gas to the appliance?
– Are other gas appliances working, gas cooker/hob for example?
– Has the credit run out on the gas pre-payment meter?
NOTICE:
On completion of the Service/Fault-Finding task which has required the
breaking and remaking of electrical connections, check:
▶ Earth continuity,
▶ Short circuit check,
▶ Polarity
▶ Resistance to earth.
10.1

10.1.1 General information

• Fault code: indicates the fault.
1.
• Fault category: indicates the fault and its effects.
Fault category O (operating code)
Operating codes indicate the operating conditions in normal operation.
Fault category B (blocking faults)
Blocking faults result in the heating system being shut down temporarily.
The heating system restarts automatically as soon as the blocking fault is
0010017100-001
removed.
Fault category V (locking faults)
Locking faults result in the heating system being shut down, and the
system can only be restarted after a reset.
▶ Press the and keys, until Reset is displayed.
The appliance resumes operation.
If a fault persists:
▶ Rectify the fault according to 10.1.2 Fault code table
Fault finding and diagnosis

Operating and fault displays

Greenstar 8000 Style – 6720883864 (2019/02)