AC Shutoff

[jmc55]

Why does my AC unit continue to run even when the room temp has satisified the thermostat setting? The unit is set at 73 degrees...the thermostat records the room temp at 73 degrees...the unit will not shutoff.

Thank you for any guidance.

[HVACJOEK]

It is something electrical, this is the time of year we hope to get these kind of calls, I'll bet there is a contractor in your area that could respond and repair your problem in four hours.

ps let us know if you need help in locating one... there are many good companies out there even outside of Lancaster Pa.

[beenthere]

Difital thermostat read outs arounded.
But, the tmp sensor is sening in tenths of a degree.
So although it may read 73°, its actually a little warmer, a few tenth. And until the temp drops those last few tenths, it will jeep the A/C running.

[pacnw]

anticipation

[Milk man]

Difital thermostat read outs arounded.
But, the tmp sensor is sening in tenths of a degree.
So although it may read 73°, its actually a little warmer, a few tenth. And until the temp drops those last few tenths, it will jeep the A/C running.

I get questioned time to time as why the room temperature and the setpoint are the same on the stat all the time. Some people don't understand that that is what we try to achieve and the system is working correctly.

[beachtech]

is it the AC or is your indoor fan set to "on" position?

is it a digital thermostat?

[jmc55]

It's the AC. Yes. a digital unit. What beenthere says makes sense, but it seems to take forever to move those tenths of degrees.

[seca750]

my heat pump system does the same thing--in heating and cooling--. could sometimes keep running for over an hour!!

[Milk man]

my heat pump system does the same thing--in heating and cooling--. could sometimes keep running for over an hour!!

How hot or cold is it outside.

At some point the heat gain in the house will equal the capacity of your equipment. 95 degrees in my area. So if your equipment is sized correctly it should run all the time at certain conditions, and loose ground on an extream day.

If one oversizes equipment in my area the equipment will short cycle and not remove enough humidity to make the space comfortable.

[jmc55]

Thank you all for your time and insight. What you say clears a lot up.

[jerrod6]

I had a Honeywell Vision Pro touch screen installed in 2004. As far as I am concerned my Tstat has always lied about the room temperature during recovery.

A few days ago I had the system off all day and then turned it on at 10:45pm. The Stat was displaying a room temp of 79F and was programmed for a sleep time of 11:30pm with a temperature of 76F. At 11:25pm I stood across from the Stat and watched. Sure enough at 11:30pm the display temperature dropped from 78F to 76F(the programmed sleep temperature) at the same time the sleep period began, however the unit ran for another two hours before turning off. Two degrees in 1 minute? Granted it was not a true recovery because the system was off, but the temperature display still dropped two degrees between 11:29pm and 11:30pm. It does this kind of display degree jumping for most of the recovery periods, so I am at the point where I just ignore what it says during any recovery.

I have a weather station in my living room which connects to my computer so I can see what the inside/outside temps and conditions are and this system also keeps history information. From this history information I see that the Stat can hold the temperature within + or – 1 degree over a period of hours. For example the temperature will gradually move between 66.5 and 67.5 over a period of 4 or 5 hours and then back down, so that’s a positive for it, but I have never been happy with the way it displays the room temperature during recovery.