I am taking bids on a new furnace and AC. The old system works fine but is 22 years old. Looking at a Trane XR13 and XR95. I will be switching from R22 to the new enviromentaly friendly refrigerant. One contractor says my old lines are fine and we can reuse them. Is there any special purging that has to be done?
Also, I have a modern programmable thermostat. Is there any benefit to buying the thermostat which comes with the system?