Groupon inspection. Supply temp 97 degree return temp approximately 65 degrees, total delta 32 degrees. Draft motor amps 2.3. Blower motor amps 6.2. Burners looggood. Could not gain. Access to flame sensing system but looks fine. Checked all tubing, eletrical connections and tighten all screws. Inspected heat exchanger found no areas of concern. Changed gas pressure from 3.4 to 3.5 w.c. checked filter it was recently changed.ac getting a 48 degree supply temp with a 70 degree return. Total delta t 22 degrees.voltage enhancement system for outdoor unit read within factory spec contactor has no pitting. operation normal at this time