Miele DA 3160 EXT Operating And Installation Instructions page 8

Warning - danger of toxic fumes
Great care should be taken when
using the cooker hood at the same
time and in the same room or area of
the house as another heating appliance
which depends on the air in the room.
Such appliances include gas, oil, wood
or coal-fired boilers and heaters,
continuous flow or other water heaters,
gas hobs, cookers or ovens which draw
air in from the room and duct exhaust
gases out through a chimney or
extraction ducting.
When used in extraction mode, with or
without an external motor fitted, the
appliance draws air in from the room in
which it is installed
neighbouring rooms.
If there is insufficient air, an
underpressure will occur. The heating
appliance may be starved of oxygen,
impairing combustion.
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from
Harmful gases such as carbon
monoxide could be drawn out of the
chimney or extraction ducting back
into the room, with potentially fatal
consequences.
In order to ensure safe operation, and to
prevent gases given off by the heating
appliances from being drawn back into
the room when the extractor and the
heater are in operation simultaneously, an
underpressure in the room of 0.04 mbar
(4 pa) is the maximum permissible.
Ventilation can be maintained by air
inlets which cannot be blocked, in
windows, doors and outside wall vents,
or by other technical measures, such
as ensuring that the extractor can only
be switched on when the heating
appliance is switched off or vice-versa.
A ventilation brick alone is not generally
sufficient to ensure safe ventilation.
The overall ventilation condition of
the dwelling must be taken into
account. If in any doubt, the advice
of a competent builder or, for gas, a
"Corgi" installer, must be sought.