Electric trench heaters are normally installed directly in front of large glass surfaces. The advantage of electric-only heaters lies in their independence of forced-circulation heating systems. The heat output produced by trench heaters is sufficient to be used either as the primary or secondary heat source. They make a perfect fit in the existing building space, in contemporary low-energy and passive homes, in electric-only houses, in buildings under construction and wherever connection to the heating system is not possible or desirable. Watch product video. Watch installation video. FET electric trench heater with fan