I have a 886 sq. ft condo and live in So. California. 2 years ago I had a Carrier Performance series furnace installed, hallway closet. It's a 2 stage furnace. For the life of me, I cannot prevent the second stage kicking in during the last few minutes. I hate the way the second stage kicks in. It sounds like a freaking jet engine. I've fiddled with the thermostat to extend the interval between first and second stages so that the second stage won't kick in. It still does.
Look, I live in So. California. My small 2 BR. (one floor) condo heats up quickly.
I don't need and don't want that second stage to kick in. I don't care if it does it to be more economical.
My old thermostat was replaced back then (vintage 1986). It had just 2 or 3 wires (if I recall). I'm wondering if the new thermostats need an additional wire in order to have full functionality, maybe not.
Can I have a tech come in and change jumpers on the furnace to force the unit not to kick into the second stage? It's kind of ridiculous now, because the second stage only kicks in during the last 5 minutes anyways, and is very loud.