We have a new home in Kansas City, MO. 2-story, approx. 2000 sq. ft (1000 up, 1000 down). We have a Lennox Merit Series furnace (I believe it's a 4-ton) & heat pump.
The home originally came with a basic, non-programable thermostat. We paid a handsome amount to the same contractor who installed the system for an X4147 thermostat.
We have the settings on cool and the fan is set on auto. Lately it has been quit warm (low to mid 90s). We set it at 77 or 78 when we're gone during the day and kick it down to 75 or 76 when we get home. We have the duct baffles set so it gets quit comfortable, sometimes chilly, both upstairs and down. We have had all of our window treatments up for more than a month.
Our problem is that the inside temp gets down to the set point usually within 30 minutes no matter how hot it has been. But once the temp has reached the set point, both the furnace and the heat pump will continue to run and run and run (sometimes more than an hour). The inside temp reading will stay at set point. After a while I will kick the set point up one degree and then the system will begin to act like it should (coming on every now and then for a little while and then shuting off). We have not placed a thermometer next to the thermostat yet but will tomorrow. I will not be surprised if the room temp gets 2 or 3 degrees lower than the set point.
We called the contractor. He really didn't say if the 'cool' should run that long after the set point but did say there could be a problem with the outside sensor or the thermostat. Funny thing is, when he originally came out and installed the X4147 he didn't install a sensor that displays the outdoor temp (unless he's talking about a different sensor). When he came out he installed a different X4147 and installed an outdoor sensor.
This is where I start to question the tech's knowledge of the X4147 or the entire system. First, he told my wife that he either forgot or did not program the original X4147. Second, the outside temp that day did not get above 93 degrees and the outside temp. on the thermostat was reading 105 degrees at 1830 hours when the temp had dropped to 89 degrees. After looking outside and not finding where he had mounted the sensor, I opened the service panel on the heat pump. The guy had just left it rolled up inside there. After removing it the temp. immediatly read correct(or close).
I called another contractor in my area who said that it's not normal for the heat pump to run for so long after the set point is reached.
Can anyone tell me if my system is running properly or if there is something the tech is missing?
Thanks for any help