Ford 2013 F-650 Owner's Manual page 113

112 Starting and Stopping the Engine
• Keep plug terminals clean and free of dirt and corrosion.
• Make sure the heater system is checked for proper operation before
winter.
Using the Engine Block Heater
Make sure the receptacle terminals are clean and dry prior to use. Clean
them with a dry cloth, if necessary.
The heater uses 0.4 to 1.0 kilowatt-hours of energy per hour of use. The
system does not have a thermostat. It achieves maximum temperature
after approximately three hours of operation. Using the heater longer
than three hours does not improve system performance and
unnecessarily uses electricity.
2013 F-650/750 (f67)
Owners Guide gf, 2nd Printing, March 2013
USA (fus)