JT Eaton Kills Bedbugs II Spray is labeled to be applied along and behind baseboards, to window and door frames, corners, pipes, storage localities, attics, crawlspaces and other areas where they tend to crawl for spiders. You should treat allow to dry before re-entering the space. We would not recommend treating the heater. Treat the surrounding cracks and crevices. It is also beneficial to apply a product outside for treatment and glueboards to the interior of the home at the entry points.