DANGER
Water temperature over 125 ° F (51 °C) can cause severe burns instantly, or death from scalds. Children, disabled,
and elderly are at highest risk of being scalded. See user's instructions before setting the water temperature.
1. Priority is given to the domestic hot water supply. A demand at a tap or shower will override any central heating requi-
rement.
2. 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 combustion fan will then come on and begin to run at ignition speed.
4. 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 the flame. In the
combustion chamber and send a signal to the control board.
5. The temperature sensors 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.
6. When the domestic hot water demand ceases the burner will extinguish, unless there is a demand for central heating.
The frost protection mode is integrated into the appliance when left in the domestic hot water or central heating posi-
tion. If the temperature falls below 41 °F / 5 °C the boiler will fire on its minimum setting until a flow temperature of 86 °F
/30 °C is reached.
With the selector switch in either, the central heating or domestic hot water position, the pump will automatically oper-
ate for 1 minute in every 24 hours to prevent ceasing.
Run the gas supply line in accordance with all applicable codes.
Locate and install manual shutoff valve before the gas valve as shown in figure 2 (F) - section 3, in accordance with
state and local requirements.
WARNING
A sediment trap must be provided upstream of the gas controls.
INSTALLATION AND SERVICING INSTRUCTIONS
3.8 DOMESTIC HOT WATER MODE
3.9 FROST PROTECTION MODE
3.10 PUMP PROTECTION
3.11 GAS PIPING
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