Appliance Operation - Potterton Promax SL range Installation & Service Instructions Manual

temperature less
than set point ?
NO
Flow switch made ?
Fan Pre-Purge.
Ignition Period.
Flame Detected ?
Burner On.
shut or Flow temperature
greater than set point ?
Fan Post Purge.
YES
shut down ?
Pump Overrun.
© Baxi Heating UK Ltd 2014
Mains On.
Flow
NO
YES
10 second
Pump On.
YES
Ignition done
YES
5 second
and less than 5
attempts made ?
5 second
Ignition done and
5 attempts made ?
YES
All TRVs
YES
5 second
All TRVs
NO
1 minute
3 minute
Anti-cycle.

3.0 Appliance Operation

3.1
1. Switched Live On: When the switched live switches
on if the flow temperature is less than the set point
then pump overrun occurs. When the switched live
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 or the TRVs
all shut down then fan post purge occurs.
6. Fan Post Purge: The pump and fan are on while the
spark generator and gas valve are off. After 5 seconds if
YES
the TRVs are not shut down then pump overrun
occurs. After 5 seconds if the TRVs are shut down then
anti-cycle occurs.
Ignition
Lockout.
7. Pump Overrun: The pump is on while the fan, spark
generator and gas valve are off. After 1 minute anti-
cycle occurs.
8. 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.
9. Ignition Lockout: The pump, fan, spark generator
and gas valve are off. The boiler can only be reset by
manually using the reset button.
9