One day during the polar vortex our townhouse had no heat. We are part of a service plan so I called Weathermakers. The service tech called me within a half hour and gave me a couple of suggestion to try until he could get there. The tech arrive 6 hours later and diagnosed the heating issue as an incorrect vent size from when ithe furnace was installed 4years earlier. He did a temporary fix so our tenant has heat until we can get this bent sizing straightened out.