Problem with digital themostat

[reco1966]

I recently had to replace my AC unit so I thought it would be a good time to replace the original 20 year old dial thermostat. I replaced it with a Hunter digital model 44360. I installed it in the spring when it started getting warm outside. I have never seen anything like this happen but when the AC is on the unit’s temp readout goes up 4-5 degrees keeping the unit from turning of the AC until around midnight. When the unit finally reaches the desired temp say 73 degrees in the hallway where the unit installed which is about 3 ft above the main return, other parts of the house are as cold as 68 degrees. I have checked this with a digital thermostat and my weather station base unit. It’s the exact opposite for the heat which is a forced air gas furnace, I set the unit at 67 degrees at night when the heat comes on it run until some parts of the house are 75 degrees also when the heat comes on the temp readout on the unit goes down by 3-4 degrees forcing the furnace turn run way too long. I manually turned it off this morning when I woke up in a sweat the hall temp on the unit said 67 the heat ran for 1.5 hours until I turned it off manually. The temp in my living room was 75. After I turned the unit off I went back a couple of minutes later and noticed the temp on the unit now said it was 72 up from 67 just a few minutes later. I am not going crazy but this thing seems to be working in reverse. I know on old dial mercury type stats you could set the anticipation setting this unit does not have anything like that I have looked all through the manual. Can somebody tell me what’s going on?

[Senior Tech]

With all due respect this is why you should let the pros take care of your HVAC needs.

You started out with a brand that is known in the industry as poor quality and now you have noone to call for support. The best action you can take is to return the thermostat where purchased and call a reputable company to take care of the issue.

[reco1966]

Well that may be true about the quality of the stat but I am an electrical engineer and I can handle installing a home thermostat. The installation really has no bearing on the unit, if its a cheap unit then please help me by telling me which unit I should get.

[kevinnn]

My guess: You really need to get a manual for that thermostat if you dont have one. Sometimes t'stats need to be configured. Also know what you are looking at for sure. Is the item on the t'stat readout the set point for heat or the temp. @ the t'sat. I think reading the operators manual would probably help if this has not been done.

[beenthere]

While it may be the thermostat causing that problem. There are other things involved with the install that create that same type of operation.

An engineer should be able to figure out what it is.

[Senior Tech]

I can respect that you are a electrical engineer, but doe's that neccesarily qualify you to diagnose HVAC equipment and controls?

Again, you need to have a thorough understanding of your system and how it operates.

I'm not trying to be hardnosed here, my only goal is to save you frustration and money in the longrun.

[fearlessfurnace]

I have not been impressed with hunter t-stats

[hvacvegas]

I have not been impressed with hunter t-stats

nor am I. Or with electrical engineers.

My grandpa was an electrical engineer at a local power plant for 40 years. He refuses to touch his ac/furnace/thermostat.

[pacnw]

has an engineer build a roof 2 feet above his heat pump.

he wondered why the unit seemed to not function as well?

in my opinion most engineers place is behind the computer at a desk, get them in the real world and they are lost.