Our house has two thermostats and two furnaces, but I wouldn’t exactly call it zone heating. Part of our house is really old – the original part of the house was built way back in the early part of last century. Then the newer part of the house was only built about ten years ago. You can imagine the difference in how well the walls are insulated in the two different sections. We find that even if we set the thermostat at the same temperature on the different sides of the house, one of the furnaces has to run much longer and work much harder than the one on the other side of the house. You can probably guess which furnace gets stuck with all of the work. It’s definitely the one that has to heat the older side of the house. We’ve had numerous HVAC technicians out to look at the issues we have here but they all say it’s a problem with the insulation, or lack thereof. There isn’t much we can do to help with the furnace running constantly on that side of the house, unless we decide to install some of that blow in insulation that you can get these days. It seems like the old insulation in the walls of our old house was nothing more than newspapers! Hopefully with new insulation we will get the furnace issue resolved because it’s very drafty here and we don’t want to have to replace one of the heating units every 5 years or so because it’s not running efficiently enough.