PREVOST H3-41 Maintenance Manual page 948

SECTION 22: HEATING AND AIR CONDITIONING
CAUTION
To avoid running down the batteries, do not
turn on the preheating system for more than
one hour before starting the engine.
WARNING
74 PA1621 Maintenance Manual All Series | Revised February 2019
The preheating system uses the same fuel as
the engine. Do not operate in a building or
while refueling. Operate only in a well-
ventilated area.