Work performed under GHAC Quality Pledge: Homeowner noticed the furnace shutting down prematurely and the inducer motor would continue to run, At that point the system would shut down and not function. Homeowner noted the furnace had allot of residual heat sitting inside of it. I arrived and checked the gas pressure and temperature rise. Everything checked out good. I did speed up the heating speed on the blower lowering the temperature rise to the low specifications. I also increased the minimum off time from 2 minutes to 5 minutes.