Safety Temperature Limiter Has Tripped - Worcester ZSBR 7-28 ICS1 Service Booklet

Rectifying faults
E 9
and

Safety temperature limiter has tripped.

Check
1. Is the heating pressure between 1
and 2 bar?
2. Is the pump blocked?
3. Is lead disconnected from one/both
safety temperature limiters?
B Power OFF the appliance.
4.
B Unplug the connector from the
cut-off device.
B Measure the NTC electrical resist-
ance.
R = ∞?
26
flashing.
yes:
no:
yes:
no:
yes:
no:
yes:
no:
Action
B Top up system.
B Vent appliance.
B Press
, does appliance restart???
E9?↓2.
↓2.
B Unblock the pump.
If pump won't start:
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change the pump.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
B Press
, does appliance restart???
E9? ↓3.
↓3.
B Power OFF the appliance.
B Connect lead.
B Turn ON the appliance.
B Press
, does appliance restart???
E9? ↓4.
↓4.
B Change the over heating cut-off device.
B Connect flue gas safety temperature limiter lead.
B Turn ON the appliance.
B Press
, does appliance restart???
E9? ↓5.
B Connect flue gas safety temperature limiter lead.
B Turn ON the appliance.
E9? ↓5.
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