The problem I'm having is that the a/c continues running - for as much
as an hour - past the past the point that the ambient temperature first
matches the set temperature.
Let's say I last set the temperature at 77F and the display says the
ambient is 77F; thus, the a/c is off. I now move the set temperature
down to 76F. The a/c stays on until the ambient reached below 75, but I
don't think that much of a swing is normal.
This Hunter 44110 thermostat has a function called Span. The manual says
this: "allows you to adjust the system ON/OFF cycle rate. The default
setting is 2 (the system cycles ON or OFF when the temperature is within
1 degree F above and below the set temperature).
I haven't adjusted the Span to 1, mainly because for the nine months
I've lived here, there was no excess run time and the temperature swing
was very low.
Sounds like I need a new thermostat. Do you agree?
Can't hurt trying to change the "span". I've never had good luck with
anything but Honeywell thermostats. The one's I have don't have a "span"
setting but don't seem to need it. Well actually they do, but it's
hidden in some of the settings like 'hot water or forced air' settings.
I had a non Honeywell in my motor home and it suffered from severe
cycle-itis. In AC mode you'd sweat before it would turn on and freeze
before it turns off. I now have a Honeywell that works great, however,
because the motor home uses DC for control and there actually a heat
pump and a totally separate furnace, setting it up is kind of weird ...
but no cycle-itis, at least.
No, I don't agree. It sounds like the thermostat is working as
intended. If it set to 76, I would expect it to start the A/C when
the temp rises to 77 and keep running until the temp reaches 75. In
other words, a span of 2. That is how mine and many others work.
The real question is what changed to make you notice something. Is is
possible, the A/C is failing such that it takes a much longer time to
cool? As another person said, you can change the span to 1 to make it
cycle twice as often. That won't hurt anything, but I suspect you
need to have the A/C unit checked out. Buying a new thermostat won't
I don't know what happened recently, say within the last week or two. I
just noticed that the a/c runs much longer. The temperature at the
supply registers is about 58F; just downstream of the evaporator it's
54F, which is the normal 20 degree drop from the return air from the rooms.
I've set the span to 1 degree and test it that way for a day or two.
Thanks to the other two guys as well.
Have you changed filters (or at least checked they're clean), made sure
the condenser fins, etc., are also clear, the outdoor unit is also free
of obstructions, etc., etc., etc., ...?
I'm in agreement with the opinion it's unlikely to be the thermostat
itself that's the culprit here.
If the AC runs longer, changing thermostat won't
It is possible the humidity is much higher, and
it's also possible the unit needs maintenance.
From here, the thermostat doesn't sound like the
Does the temp swing more than a couple degrees? It
could be your thermostat, or could be some other
part of the system going bad. Seriously, two degree
swing is just fine for most folks.
I knew some folks, I visited.It was hot in the house,
and they had just returned the defedive thermostat 3rd
time, they were on the 4th stat. I got permission to
look around, and found a sticky relay on the furnace
You may be asking for too much, with one degree swing.
On Thursday, July 16, 2015 at 9:51:08 AM UTC-4, songbird wrote:
His problem is the range of swing, not the set temp. Solution is
to change the swing parameter from 2 deg swing to 1 deg. IDK why he
didn't just try it. If that results in too many start/stops,
then I guess it's time for a better thermostat. I've had very
good experience with Honeywell VisonPro.
Why shoudln't I pile on?
So you didn't have a problem so you didn't change the setting and now
you do have a problem but you still don't want to change the setting
even though that might be what the setting is for, and are considering
buying a new one. Not a good plan, for thermostats and other problems
It sounds OK to me. The display of my thermostat shows when it's
calling for heating or cooling. That can be very helpful.
My swing doesn't seem to be adjustable. Sometimes if the thermometer
says 79 and I step down the setting to 78, it doesn't always come on. A
reading of 79 may mean 78.6, and 0.6F may not be enough to turn it on.
For efficiency, an air conditioner should be sized to run continuously
on the hottest, most humid afternoon. When it's 90 and humid, mine may
run only a few minutes at a time and cost a dollar or so a day. If it's
in the high 90s, and the dew point is high, and the house has been
baking in the sun for hours, and there's a breeze to increase
infiltration of hot, humid air, it may run continuously.
My thermostat is mounted on an old-fashioned plaster wall. Behind the
wall is a closet that may be hotter than the room. That can cause the
air conditioner to take longer to satisfy the thermostat.
On hot afternoons when it runs a lot, I may let relative humidity be my
guide and step up the thermostat a degree at a time. As long as the air
conditioner runs enough to hold down the humidity, a couple of degrees
warmer will be fine. If I've let the temperature rise in the afternoon,
I can step it down at night so the air conditioner will run enough to
control the humidity.
On Thursday, July 16, 2015 at 4:05:13 PM UTC-4, J Burns wrote:
You have your stat set at 79? Holy crap!
Anything above 74-75 outside for more than a few hours and our A/C is on and
set for 70. On the flip side, winter heat is set for 68. (We'd do 68 in the
summer too but even I can see the economic foolishness of that!)
The last few nights have been in the 50's. We have our windows open and a
fan drawing air into the bedroom. That's why God invented comforters and
Do you turn the heat on when the night temps dip into the 60's?
On Thu, 16 Jul 2015 13:25:25 -0700 (PDT), DerbyDad03
Down to 8C overnight last night, and expecting 31C tomorrow
afternoon. Furnace and AC both turned off - dehumuidifier running in
the basement when hydro rate is mid - low - never when on high rate.
If the humidity is high and it goes over 31C the AC might get turned
79 in the morning would probably be way too humid, but I may edge it up
to 81 in the early evening, when the AC is running enough to control the
Sometimes I'll run the AC when it's cooler than 74 outside (and inside),
if the relative humidity is too high. Trying to _keep_ the house that
cool could mean a bigger battle with relative humidity.
I do that whenever possible. The dew point, which may be quite different
than what the National Weather Service measures 10 miles from here,
determines how far it's feasible to cool the house that way. As outside
air cools the interior, relative humidity will rise. When it gets high,
the natural fibers in wood, textiles, and paper can absorb a lot of
moisture. It can be hard for the AC to get rid of all those gallons of
water after I close the windows.
I was curious so I went to Amazon. From there, I went to Honeywell for
an owner's manual.
It has a 5" flexible hose and a flattened window nozzle with an adapter
to adjust to your window width. Amazon customers say you can leave your
There doesn't seem to be a hose to bring in outside air to cool the
condenser. If it sucks hot, humid outside air into the room to replace
the exhaust air, it sounds like it wouldn't cool the room very well.
That's my general impression. What's the point
of dumping hot air out the hose in the back,
if the room needs to draw in replacement hot air?
I've heard the "on wheels" units also have a
condensate pan that needs to be dumped out, like
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