Baxi Barcelona System, Installation And Servicing Instructions

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3.0 Appliance Operation - Page 6
3.1
1. Pump Overrun: When the switched live to the boiler
switches on or the flow temperature is greater than the set
point or anti-cycle finishes then Pump Overrun occurs for 10
seconds (cold) or 60 seconds (hot). The pump is on while
the fan, spark generator and gas valve are off.
2. Fan Purge: When pump overrun has finished if the flow
temperature is less than that set on the thermostat knob then
Fan Purge occurs. The pump and fan are on while the spark
generator and gas valve are off.
3. Ignition: When fan purge has finished Ignition occurs.
The pump, fan, spark generator and gas valve are on. The
burner ignites at mid rate.
4. Burner On: When a flame is detected during the ignition
period then Burner On occurs. The pump, fan and gas valve
are on while the spark generator is off. Flow temperature is
controlled by varying the fan speed (and thereby the gas
rate) to achieve optimum operation.
5. Anti-cycle: When all the TRVs shut down during Burner
On or Pump Overrun finishes and flow temperature is
greater than set point then Anti-cycle occurs. The pump, fan,
spark generator and gas valve are switched off.
6. Ignition Lockout: When 5 ignition attempts have been
made without a flame being detected then Ignition Lockout
occurs. The pump, fan, spark generator and gas valve are
switched off. The lockout light flashes once a second. The
boiler can only be reset manually using the thermostat knob.
7. No Water Flow: When there is No Water Flow through
the boiler (indicated by the flow switch) then a continuous
cycle of Pump Overrun and Anti-cycle occurs.