5 Operation
5.2
Shutdown
5.2.1
Switching off the heating and domestic hot water (DHW)
Heating mode can also be disabled by turning the
until the word OFF appears on the display.
Important
When heating mode is re-enabled check, by turning the knob, that
the comfort temperature is that requested.
Important
Heating is disabled but the frost protection function remains
activated.
Domestic hot water mode can also be disabled by turning the
knob anti-clockwise until the word OFF appears on the display.
To switch the boiler off completely, switch off the power supply to the
appliance and close the gas cock.
Important
In this condition, the boiler and the heating installation are not
protected against frost.
knob anti-clockwise
5.3
Frost protection
It is a good idea to prevent the heating installation from draining
completely, as changing the water can result in unnecessary and
damaging limescale deposits from forming inside the boiler and heating
elements. If the thermal installation is not intended to be used during the
winter months and there is a risk of frost, we recommend mixing suitable
antifreeze solutions designed for a specific purpose (e.g. propylene glycol,
which contains limescale and corrosion inhibitors) into the water in the
installation. The boiler's electronic control system is equipped with an
"antifreeze" function for the heating system. This function activates the
boiler pump when the heating system flow temperature falls below 7 °C. If
the water temperature reaches 4 °C, the burner is switched on, bringing
the system water to a temperature of 10 °C. When this value is reached
the burner switches off and the pump continues to operate for another 3
minutes.
Important
The frost protection function will not work if there is no power
being supplied to the boiler or if the gas supply cock is closed.
400 Combi 2
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