Boiler Schematic - Baxi LUNA DUO-TEC 1.70 User Manual

2.8

BOILER SCHEMATIC

• With a demand for heating, the pump circulates water through the primary circuit.
• The combustion fan will then come on and begin to run at ignition speed.
• Once the fan reaches ignition speed the control board will allow power to flow to the spark generator and gas valve creating
ignition in the combustion chamber. The flame sensor will acknowledge the presence of a flame in the combustion chamber
and send a signal to the control board.
• The temperature sensor will send a signal to the control board allowing the control board to increase / decrease the speed of
the fan. The combustion fan will in turn modulate the gas rate accordingly.
• Once the central heating loop temperature exceeds the central heating loop setpoint the unit will shutdown and go through a 3
minute time delay (burner pause time) before another call for heat.
• During this time the pump will run for an additional three minutes to dissipate any residual heat.
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