How to Make the Coils Hotter in an Electric Furnace

Turn the thermostat up to the maximum setting on the furnace. The coils will reach their peak temperature and hold it for a longer period of time.

Repair any cracks or air leaks in the furnace, especially where the coils are located. If warm air is escaping the system, cooler air is also entering the furnace through these same cracks, and the coils may be losing heat. A leak-free furnace is more effective at heating your home and also runs more efficiently, which lowers utility costs. Cracks in the furnace core should be checked by a professional, but mastic and metal tape work effectively on duct leaks.

Replace the furnace's air filters. Clogged air filters limit the furnace's performance, and the blocked airflow often leads to furnace shutdown before the coils achieve their maximum heat output. Replacing the filters helps the coils and the furnace, as a whole, operate at peak efficiency. For best performance, change the filter every four to six weeks during the heating season.