Table of Contents
Advertisement
18. Fault Finding
Note: This information is for guidance only. Worcester Heat
Systems cannot be held responsible for costs incurred by per-
sons not deemed to be competent.
Preliminary Checks.
Electrical system checks are the first actions to be
carried-out during a fault finding procedure. On
completion of the Service or a fault finding task which has
necessitated the breaking and remaking of electrical
connections, check (a) Earth Continuity, (b) Short Circuit, (c)
Polarity, (d) Resistance to Earth.
INDICATOR
CH Light Flashes
Slow
CH & DHW Lights Flash
Slow
CH Light Flashes
Fast
DHW Light Flashes
Fast
Fault Finding Chart
Select the appropriate indicator light situation. Refer to the appropriate section of the chart. This system assumes that the appliance has
been operating correctly upto the point of failure.
FAIL POINT C
FAIL POINT D
FAIL POINT F
FAIL POINT G
FAIL POINT H
FAIL POINT I
RESULT
Burner Lock - Out.
Flame Detect Fault.
Internal TestFault.
Primary Overheat.
Overheat Thermostat Operated in
Demand status.
Sensor Fault.
Primary (CH) or DHW Sensor Open
or Short Circuit.
Internal Reference Voltage Error.
Air Pressure Fault or
APS Permanently Closed.
Blocked Flue or
APS Does not Close.
Water Pressure Fault
APS Open While Burner is On.
Low Water Pressure.
LIGHT SITUATION DURING FAULT
No green light
(Red lights work)
(Other lights work)
Light on constant
(CH knob in OFF
Flashing slow
Flashing fast
POWER ON
CH DEMAND
(Green)
Other faults not covered by above
Other faults not covered by above
The electronic control system for this appliance uses the four
lights on the facia. These show the normal operating status and,
by flashing, help to provide a fault diagnostic system. With
individual or groups of lights being permanently off, on or
flashing, every normal fault can be identified.
Slow Flash - One per second
Can be cleared by pressing the facia reset button for at least one
second.
Fast Flash - Five per second
Can be cleared by removing the fault and/or switching the
mains off and on.
CAUSE
No lights at all
No red lights
(Green light working)
No light
No light
(Other lights work)
position)
2 lights flashing slowly
Flashing fast
HW DEMAND
(Red)
(Red)
29
ACTION
Press Facia Reset Button For 1 Second.
As Above.
Switch Mains Supply Off /On
or Rectify Fault.
Switch Mains Supply Off/On
or Recify Fault.
FAIL POINT A
FAIL POINT B
FAIL POINT E
FAIL POINT J
BURNER ON
(Red)
FAIL POINT K
FAIL POINT K
Advertisement
Table of Contents
