Sequence Of Operation - UTICA BOILERS SSC UBSSC-075 Installation Operation & Maintenance

2.4 Sequence of Operation

Operational State
No
Heat
Demand?
Yes
DHW CH
Pump on
No
Supply
Temperature
<Setpoint?
Yes
15 Second
Prepurge
Ignition
Sparking
After 2 seconds
APPENDIX A - CONTROL MODULE
Front
Panel
User Interface Display
Indica-
tors















72
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.