This heater I have is rated at 1800 watts. Before i plug it In I would like to know if the older wireing system here will be able to handle it (positive and negative wires only in any one outlet). What is the best way to figure for that ? Every outlet in this place is a GFCI (Bdrms.,living room,kitchen and 1 in bathroom) or will this type of outlet trip if to much or not enough juice Is detected at outlet ? Thank you