Boiler Schematic - Baxi LUNA HT 1.1000 Notice D'installation Et D'entretien

Central Heating Mode (Fig. 1)
1. With a demand for heating, the pump circulates water through the primary circuit.
2. The combustion fan will then come on and begin to run at ignition speed.
3. 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 com-
bustion chamber and send a signal to the control board.
4. 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.
5. 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.
6. During this time the pump will run for an additional three minutes to dissipate any residual heat.
Fig. 1
INSTALLATION AND SERVICING INSTRUCTIONS

2.8 BOILER SCHEMATIC

9
Legend:
1 boiler drain point
2 pressure gauge
3 condensate trap
4 central heating NTC sensor
5 105 °C / 221 °F overheat
thermostat
6 gas valve
7 heat exchanger
8 flame sensor electrode
9 burner
10 ignition electrode
11 air/gas mixture header
12 mixer with venturi
13 gas diaphragm
14 fan
15 flue thermostat
16 coaxial fitting
17 automatic air vent
18 low water cutoff
19 air pressure switch
7110243.01 - en