We have the York Diamond 80 gas furnace. Ongoing problem with setting the termostat at 68 and it will only register 59-60 degrees. Checked the furnace and it appears to be firing O.K. Contacted the Rite Temp Therm company and their customer service reps all told me the same thing. To reset the thermo and hit the Hold button then set the desired temp. This would by-pass the programmed cycles, etc. I have done this several times over the past few days and it does not change the temperature on the thermostat or in the rooms. I also replaced the batteries without success. Any thoughts?? Thanks, Art