For 8 button stats you press the MODE and PROGRAM buttons simultaneously. For 4 button stats you press the MODE and FAN for Residential thermostats, press MODE and OVERRIDE for Commercial thermostats. For 4 button stats the 2 buttons must be pressed simultaneously for 10 seconds, then keep pressing the MODE button for each additional step.
There are different warranties for different units, but the standard warranty is 5 years on the compressor and 1 year on all the other parts. Most furnaces also have a 20 year warranty or longer on the heat exchanger. No labor warranty is included except 1-year labor warranty if provided by the installing contractor.
