The best replacement for auxiliary heat is emergency heat.

The best alternatives to auxiliary heat are rated as following:
★★★★★  emergency heat
★  heat pump

Your alternative for auxiliary heat is not listed? Suggest!
Speaking about auxiliary heat, one probably shouldn't forget about heat pump.

Other search terms related to auxiliary heat and their ratings are:
★★★★★ heat pump
You have in mind a companion for auxiliary heat and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of auxiliary heat in all years. Click on graph for more.
auxiliary heat
emergency heat
heat pump