Dear Webasto Customer,
We presume that the principle and mode of operation of your new heater has been explained
to your complete satisfaction by the workshop/service centre which installed the heater. In
these operating instructions we would like to once again provide you with an overview of the
safe use of the heaters.
Within the territory governed by European Directive 70/156/EEC and/or EC/2007/46 (for new
vehicle types from 29/04/2009), there are homologation approvals for the Thermo 90 S water
heaters in accordance with the directives 2001/56/EC (Heating systems) and 72/245/EEC
(EMC) and for the Thermo 90 ST water heaters in accordance with EC
E-R 122 (
Heatings) and
ECE-R 10 (EMC).
The units
must be installed in accordance with the enclosed installation instructions. The in-
stallation must be checked in accordance with statutory installation provisions. Refer to the
installation instructions for more details.
The year in which the heater was used for the first time must be permanently displayed on
the type label by deleting the inapplicable years from the label.
When installing the Thermo 90 S / Thermo 90 ST heater in vehicles for transporting dangerous
goods, the requirements of the ADR in the respectively valid version must also be complied
with in addition to the German Road Traffic Regulations (StVZO).
The heater must not be operated :
• In filling stations and tank farms.
• At locations at which highly flammable gases or dusts can
form, and at locations at which highly flammable liquids
or solid materials are stored (e.g. near fuel, coal and wood
dust, grain warehouses, dry grass and leaves, cardboard ,
paper, etc.)
• In enclosed rooms (e.g. garages), not even via the timer or
Telestart.
The heater must not:
• be exposed to storage temperatures of more than +85 °C.
Otherwise the electronics may suffer permanent damage.
• Be operated without at least 20 % brand name anti-
freeze in the water of the heating circuit.
General Information
Maintenance and Safety Instructions
Danger of explosion
and suffocation!
Operating Instructions
Thermo 90 S
Thermo 90 ST