Operating instructions

71
1.4 Sequence of Operation
Operational State User Interface Display Explanation
Boiler operates in standby mode
until demand for Central Heat
(CH) or Domestic Hot Water
(DHW) is detected.
CH or DHW pump is turned
on based on type of heating
demand.
(CH call is illustrated)
Control Module compares
supply Temperature to set
point. Boiler proceeds to
ignition if supply temperature is
less than set point.
Combustion Air Blower speed
modulates to pre-purge setting
for 15 seconds.
Sparking initiated sequence.
Heat
Demand?
DHW CH
Pump on
Supply
Temperature
<Setpoint?
15 Second
Prepurge
Ignition
Sparking
No
Yes
No
Yes
After 2 seconds
APPENDIX A - CONTROL MODULE