FORD 2013 F-550 v.3 - Manual (Page 187)

Important Ventilating Information
If you stop your vehicle and leave the engine idling for long periods of
time, we recommend that you do one of the following:
• Open the windows at least 1 inch (2.5 centimeters).
• Set your climate control to outside air.
ENGINE BLOCK HEATER (IF EQUIPPED)
WARNING: Failure to follow engine block heater instructions
could result in property damage or physical injury.
WARNING: Do not use your heater with ungrounded electrical
systems or two-pronged (cheater) adapters. There is a risk of
electrical shock.
Note: The heater is most effective when outdoor temperatures are below
0°F (-18°C).
The heater acts as a starting aid by warming the engine coolant. This
allows the climate control system to respond quickly. The equipment
includes a heater element (installed in the engine block) and a wire
harness. You can connect the system to a grounded 120–volt A/C
electrical source.
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 suitable for use 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.
186 Starting and Stopping the Engine
2013 F-250/350/450/550 (f23)
Owners Guide gf, 3rd Printing, December 2012
USA (fus)