FORD 2013 F-550 v.1 - Manual (Page 187)

We recommend that you do the following for safe and correct operation:
• Use a 16-gauge outdoor extension cord that is product certified by
Underwriter’s Laboratory or Canadian Standards Association. This
extension cord must be able to be used outdoors, in cold
temperatures, and be clearly marked Suitable for Use with Outdoor
Appliances. Never use an indoor extension cord outdoors; it could
result in an electric shock or become a fire hazard.
• Use as short an extension cord as possible.
• Do not use multiple extension cords.
• Make sure that when in operation, the extension cord plug and the
heater cord plug connections are free and clear of water. This could
cause an electric shock or fire.
• Make sure your vehicle is parked in a clean area, clear of
combustibles.
• Make sure the heater, heater cord and extension cord are firmly
connected.
• Check for heat anywhere in the electrical hookup once the system has
been operating for approximately 30 minutes.
• Make sure the system is unplugged and properly stowed before driving
your vehicle. Make sure the protective cover seals the prongs of the
block heater cord plug when not in use.
• 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.
186 Starting and Stopping the Engine
2013 F-250/350/450/550 (f23)
Owners Guide gf, 1st Printing
USA (fus)