On Monday, September 18, 2017 at 12:24:30 AM UTC-4, wrote:
Thank You Vic and trader_4 for your specificity. I am so upset about this situation, so helpful answers are appreciated. As a single female, I'm tired of getting screwed by contractors. The upsell of the 2.5 ton unit for my small place was where the problems started. It sounded like a jet was taking off in my living room every time the blower started. The humidity is so high, I have to run the A/C until I'm freezing here at 68 or 69 degrees to get it down to 55%. Since I complained to the contractor right away, they replaced the components outside with smaller ones, but I don't think that helped. At this point I'm not sure what is reasonable to ask them to do. I believed them when they said "stuff happens" when the blower motor went out a couple of weeks ago when the thing was only 13 months old. Reading these threads and some articles, I'm finding out just how hard it is on certain components like motors and such when its constantly starting from zero. Someone likened it to turning your car off at every stop light. So, I will no longer buy the "stuff happens" theory especially if someone can tell me my system is short cycling. Today it was in the lower 80s outside. I was trying to maintain a 74 degree temp. The A/C was on for 3-7 minutes and off for 7-12 minutes, most of the day. BTW, the thermostat is in a little hallway. No sunlight, drafts or vents. And also, the lower bills I was promised never happened. My new, high efficiency system is not so efficient. Since the system is new, replacing it is not a cost-effective option. Maybe your advice regarding a thermostat that can "stretch" the cycle a bit could save on some wear and tear.

While it's true that short cycling puts more strain on the motors and isn't as efficient, it's not why your motor failed in just one year. It might make a difference of it lasting 15 years instead of 20 or something like that, but not failing in just a year. Was it a basic motor or the new fancy variable speed ECM type? The latter is more failure prone. I had the ECM fan on the outdoor condenser go on my theme after just 2 years. That's what you get in the quest for higher seers. I replaced it myself for $90 with a basic standard motor, which was available from many sources and fit. A new ECM one would have cost 3x or 4x that.

If you replace the thermostat and stop the short cycles, you may notice an improvement in energy use too. Download the install manuals for any new ones you're considering. I know on the Honeywell vision pro you can set the number of cycles per hour. They also have adaptive recovery, where after having the thermostat set back, when you set the time for it to resume, you pick the time and temp you want and it figures out how much earlier to start it to reach that temp at that time,based on history and current conditions..