This website points to a recall of specific Delonghi manufactured oil filled heaters.
Follow these 4 steps to determine if your heater is in the recall.

Fatal-Oil-Heaters-Manufactured-by-DeLonghi

What should you do if you think your heater has been recalled?
CLICK THIS LINK AND FOLLOW THE INSTRUCTIONS ON TO THE UNITED STATES CONSUMER PRODUCT SAFETY COMMISSION WEBSITE.
Click here if you have a recalled heater