Checked thermostat. Recorded serial number. Adjusted venting to increase pitch. Venting was pitched down the wrong way. Found humidifier not operating. After checking thermostat, found incorrect wiring to unit. Wired to main terminal and transformer. Cycled, operating normal at this time. Furnace start up. Cycled system. Checked incoming and outgoing gas pressures. Adjusted to maximize efficiency. Checked wiring. Temp rise normal. Preformed combustion test and found normal levels, system operating normal at this time. Job complete.