We did not run the heat after the installation was complete and just recently started our pellet stove. Our house is so much more comfortable after the job that this company did . The attention to detail and the quality impressed me. The whole house fan where we used to lose a lot of heat has an enclosure built out of foam insulation with a lid secured by Velcro, what a difference. I was not expecting that we would notice such a improvement in the comfort of our home.