DIAGNOSIS A slightly warm plug is normal under high load. A hot plug indicates high resistance, often from a loose outlet connection or a worn household receptacle.
FIX Unplug the heater. Inspect the plug blades for discoloration or pitting. Plug the heater directly into a wall outlet, not an extension cord or power strip. Test a different, high-capacity household outlet on a different circuit. The plug should be no more than slightly warm.
IF THAT DIDN'T WORK The issue may be internal wiring at the plug connection point inside the heater. This requires inspection by a technician.
HEADS UP A hot plug is a fire hazard. Discontinue use immediately if the plug is too hot to hold comfortably.