Worcester Greenstar Heatslave II External 12/18

FAULT FINDING
& DIAGNOSIS
FAULT FINDING & DIAGNOSIS
BLOCKING ERROR
INSTALLATION & SERVICING INSTRUCTIONS FOR GREENSTAR HEATSLAVE II EXTERNAL 12/18-18/25-25/32
6 720 805 210-01
56
FAULT FINDING & DIAGNOSIS
BLOCKING ERROR
Blocking Error:
Should a fault develop with this boiler (or the
system), the boiler will enter into a Locking or
Blocking condition.
Blocking condition:
l The boiler will stop operating and no fault
code will be displayed.
l An alpha numeric fault code is accessed
in the info menu by pressing the
spanner/return button.
NOTE: Unlike a Locking error, during a
Blocking error (or normal operating
status), a fault code is not automatically
displayed.
l A 3 digit cause code is also accessed in
the info menu by pressing the
spanner/return button.
l The condition will clear automatically when
the associated fault clears e.g. waiting for
an area to cool.
l In some cases a Blocking error has a
defined time durationprior to changing to a
Locking condition.
Fault
code
Cause
code
Description
Possible cause
D4
271
Temperature difference
between flow and
safety sensors exceeds
limit
The temperature of the primary flow and the safety
sensor on the main heat exchanger should be within
15°C of each other.
E9
276
277
Flow temperature
exceeds 95°C
Safety temperature
exceeds 95°C
Primary overheat - boiler waits for temperature to reduce;
if not it becomes a Locking error.
Main heat exchanger safety sensor overheat - boiler waits
for temperature to reduce; if not it becomes a Locking
error 219.
No
code
212
380
359
Safety or flow temperature
rises too high
Inlet DCW temperature
higher than DHW outlet
temperature
DHW outlet or storage
tank exceeds 90°C
Air lock or reduced water content.
The output is blocked until the inlet temperature drops
below the output temperature.
Pump and burner are blocked until temperature drops
to < 89°C.
F0
263
Appliance powered off
with Locking fault present
Locking fault present when powered off.
Fault Codes - Blocking error: