Appliance Operation - Baxi System 100 HE Plus Installation & Servicing Instructions Manual

NO
8
Switched Live
to Boiler On.
Flow
temperature less
than set point ?
YES
10 second
Pump On.
Flow switch made ?
YES
YES
5 second
Fan Pre-Purge.
5 second
Ignition Period.
Flame Detected ?
YES
Burner On.
NO
1 minute
Pump Overrun.
3 minute
Anti-cycle.
NO
Ignition done
and less than 5
attempts made ?
Ignition done and
5 attempts made ?
YES
Ignition
Lockout.
All TRVs
shut down ?
YES

3.0 Appliance Operation

3.1
1. Switched Live To Boiler On: When the switched live
switches on if the flow temperature is less than the set
point then pump on occurs. When the switched live to
the boiler switches on if the flow temperature is greater
than the set point then pump overrun occurs.
2. Pump On: The pump is on while the fan, spark
generator and gas valve are off. After 10 seconds if the
flow switch has made then fan pre-purge occurs. After
10 seconds if the flow switch has not made then anti-
cycle occurs.
3. Fan Pre-Purge: The pump and fan are on while the
spark generator and gas valve are off. After 5 seconds
ignition occurs.
4. Ignition: The pump, fan, spark generator and gas
valve are on. If a flame is detected then burner on
occurs. If a flame is not detected within 5 seconds and
less than 5 ignition attempts have been made then fan
purge occurs. If a flame is not detected within 5 seconds
and 5 ignition attempts have been made then ignition
lockout occurs.
5. Burner On: 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. If the flow
temperature is greater than the set point then pump
overrun occurs. If the TRVs all shut down then anti-
cycle occurs.
6. Pump Overrun: The pump is on while the fan, spark
generator and gas valve are off. After 1 minute anti-
cycle occurs.
7. Anti-cycle: The pump, fan, spark generator and gas
valve are off. After 3 minutes if the flow temperature is
less than the set point then pump on occurs. After 3
minutes if the flow temperature is greater than the set
point then pump overrun occurs.
8. Ignition Lockout: The pump, fan, spark generator and
gas valve are off. The boiler can only be reset by
manually using the reset button.