Webasto HL 90 Notice D'utilisation Et D'entretien page 18

The unit must be installed as set out in the supplied installation manual.
The year in which the heater is used for the first time must be permanently
recorded on the heater's rating plate by deleting the inapplicable year figures.
GB
Check the openings of the combustion air inlet lines and exhaust pipe opening
and clean them if they are dirty.
Switch off the auxiliary heater before refuelling.
The air heater's heat exchanger can be used for a maximum of 10 years and
must then be replaced by the manufacturer or one of its authorised workshops
using a genuine spare part. A label must then be affixed to the heater showing
the date of sale of the heat exchanger and the wording "Genuine spare part". If
exhaust pipes pass through compartments used by people, the pipes must also
be replaced by genuine spare parts after 10 years.
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