Table Of Operation And Fault Displays - Bosch Worcester 2000 Series Installation And Maintenance Instructions Manual

Fault finding and diagnosis
11.2

Table of operation and fault displays

Description
200 O The device is in central heating mode.
201 O The appliance is in DHW mode.
202 O The appliance is in optimised switching mode:
the interval for restarting the burner has not yet
expired ( service function 3-b2).
203 O The appliance is on standby, there is no heat
demand.
204 O The current flow temperature is higher than the
set flow temperature. The burner has been
switched off.
207 – Operating pressure too low.
208 O The appliance is in chimney sweep mode.
Chimney sweep mode is deactivated
automatically after 30 minutes.
212 – Temperature increase for safety or flow
temperature sensor too fast.
214 V The fan stops during the safety time.
215 V Fan too fast.
224 B Flue gas temperature limiter or heat exchanger
224 V temperature limiter has tripped.
227 B No flame detected.
227 V
228 V Flame signal is present although burner is
switched off.
64
Remedy
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▶ Fill and vent the system, check the system for leaks.
▶ Replace pressure sensor if necessary.
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▶ Open the shut-off valves.
▶ Check fan, replace if necessary.
▶ Check mains voltage.
▶ Replace fan.
▶ Mains voltage must correspond to the default value.
▶ Check PCB and fan harness, replace if necessary.
If the blocking fault persists for a prolonged period, it becomes a locking fault.
▶ Check position of isolation valve in heating circuit, open if required.
▶ Check water pressure, if necessary top up until the preset pressure is reached.
▶ Check the temperature limiter and connecting lead of the heat exchanger for
breaks, replace if required.
▶ Check the flue gas temperature limiter and the connecting lead for breaks, replace
if required.
▶ Vent appliance with service function 4-A1 ( page 48).
After the 5th ignition attempt, the blocking fault becomes a locking fault.
▶ Check whether the gas isolator is open.
▶ Check the gas supply pressure.
▶ Check ionisation signal.
▶ Check the power supply.
▶ Check the electrodes with cable, replace if required.
▶ Check the flue system, clean or repair if required.
▶ Check gas/air ratio, adjust if necessary.
▶ Clean heat exchanger.
▶ Check the gas valve, replace if required.
▶ Check burner setting, correct if necessary.
▶ Check if there is a flame present.
▶ Check electrodes and connecting leads, replace if required.
▶ Check the gas valve, replace if required.
▶ Check appliance electronics, replace if necessary.
Worcester 2000 – 6 721 814 551 (2019/09)