Not exactly. Let's deal with one season at a time and that should make it a little easier to follow. In the summer, you set the programmable thermo to the energy saving temp of your choice, let's say 85 degrees. This will be the temp that is in use when u are all away from, the house. It will also be programmed with the exact temperature (let's say 78 degrees) that your family finds comfortable, but it will be scheduled to use that temp ONLY when you are certain that someone will be home (10 pm to 6 am or such). The manual thermo is set to a few degrees below that number (say 72 degrees). When someone is on their way home early, they can call (if you have a telephone controller) and activate the universal module which will connect the manual thermo to the HVAC unit. When it comes on, the HVAC will come on and start cooling off the house. By the time they get home, the house will be cool. When the house gets colder than you want (below 78 degrees) you will notice that the manual thermo is still engaged and remember to send the x10 signal to turn off your universal module.
In the winter, you set the programmable thermo to the energy saving temp of your choice, let's say 68 degrees. This will be the temp that is in use when u are all away from, the house. It will also be programmed with the exact temperature (let's say 74 degrees) that your family finds comfortable, but it will be scheduled to use that temp ONLY when you are certain that someone will be home (10 pm to 6 am or such). The manual thermo is set to a few degrees above that number (say 80 degrees). When someone is on their way home early, they can call (if you have a telephone controller) and activate the universal module which will connect the manual thermo to the HVAC unit. When it comes on, the HVAC will come on and start warming up the house. By the time they get home, the house will be warm. When the house gets hotter than you want (above 74 degrees) you will notice that the manual thermo is still engaged and remember to send the x10 signal to turn off your universal module.
As I said earlier, "The only problem I have is when the weather changes are severe enough that I'm switching from heat to A/C.", But once summer is really here, it runs great, likewise, once it truly turns to winter, this works well.