Domestic Hot Water Mode; Frost Protection Mode; Pump Protection - Baxi Luna 3 Comfort Series Installation And Servicing Instructions

Domestic Hot Water Mode (Fig. )
1. Priority is given to the domestic hot water supply. A demand at a tap or shower will override any central heating requi-
rement.
. The flow of water will operate the DHW flow switch which requests the 3 way valve to change position. This will allow
the pump to circulate the primary water through the DHW plate heat exchanger.
3. The burner will light automatically and the temperature of the domestic hot water is controlled by the temperature
sensor.
4. When the domestic hot water demand ceases the burner will extinguish and the diverter valve will remain in the dome-
stic hot water mode, unless there is a demand for central heating.
Key
1 Primary Heat Exchanger
2 Burner
3 Ignition Electrode
4 Flame Sensing Electrode
5 Gas Valve
6 Pump
7 Automatic Air Vent
8 Expansion Vessel
9 Plate Heat Exchanger
10 Flow Sensor with Filter
11 Boiler Drain Point
12 Pressure Relief Valve
13 Heating Return
14 Cold Water Inlet On/Off Valve and Filter
15 Gas Inlet
16 Domestic Hot Water Outlet
17 Heating Flow
18 Automatic By-Pass
19 Water Pressure Switch
20 Manometer
21 Domestic Hot Water Temperature Sensor
22 Three Way Valve
23 Three Way Valve Motor
24 Safety Thermostat
25 Central Heating Temperature Sensor

Frost protection Mode

1. Boilers electronic management includes a "frost protection" function in the central heating system which operates the
burner to reach a heating flow temperature of 30°C when the system heating flow temperature drops below 5 °C. This
function is enabled when the boiler is connected to electrical supply, the gas supply is on and the system pressure is as
required.

pump protection

1. In the event that no heat is required, the pump will automatically start up and operate for one minute during the fol-
lowing 24 hours. This function is operative when the boiler is powered.
InstructIons pertaInInG to tHe Installer
Domestic Hot Water circuit
Fig. 
9
95.188.3 - GB