I have had my two ClimateMaster geothermal systems for almost 5 years now and have had my share of issues. My choice of geothermal was from necessity, I have no gas in this area and propane or oil were not good choices in my opinion. Generally I am pleased with my choice. My energy consumption seems to be good when I compare my bills with other homes of similar size in our climate. And although we have always been fairly comfortable I am still looking to reach a little better comfort level and still trying to manage my own expectations. Over the years I have received a lot of good information from this site and, even if it didn't always appear that way, I have appreciated that info and acted on it as much as I could. I have added an outdoor reset to my water-to-water side and I'm trying to work up the courage and budget to make some improvements to my manifold system. On the water-to-air side I have switched to an Ecobee thermostat. My question today is hopefully a simple one. I realize there can be many variables in heating scenarios but assuming a very well insulated house and a properly sized system what would be a reasonable time lapse from the call for heat to setpoint where the tStat differential is .03C and the outdoor temperature is 0C. Thanks.