On Dec 28, 9:05*pm, "Stormin Mormon"
wrote:
Just for fun, crank the thermostat up as high as it will go,
and see if the house warms. Please write here, and let us
know if that warms the house.
--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.
"JoeSpareBedroom" wrote in
...
If my thermostat's been set to 64 or 65 all day and I bump
it up to, say,
68, I find maybe 20 minutes later that the house temp
(measured at the
thermostat) is still where it was before raising the
setting. Sometimes a
bit lower, because I also find that the furnace is blowing
cold air. But
before I raise the setting, the temp shown on the thermostat
matches the
lower temp it was set at before. So, I know that while I was
away, the
system was maintaining the lower temp correctly.
I've only noticed this for the past couple of days, and I've
been too busy
when arriving home to check & see if the furnace blew ANY
warm air in the
first few minutes after raising the temp. When it's
functioning correctly,
there's warm air within 30 seconds of the furnace turning
on. With the
partial information I've provided, does this sound more like
a thermostat
issue or a problem with the furnace?
The thermostat is an Aprilaire 8363 (digital, controls
furnace and AC).
Installed by reputable contractor. The gas furnace is a 12
year old Goodman
installed by a contractor hired by previous homeowner. It's
been serviced by
my choice of contractor for the past 8 years.
If you have it set to 64 and it's cold outside, after your bump it
up, it could take 20+ mins for the thermostat
to show 65. Worst case, the temp before it starts might have been
almost enough to have the thermostat
show 63. In which case it has to go up almost 2 degrees before it
will show 65. I have a gas furnace that
is on the large size for my house and it raises the temp about 5.25
degrees an hour.
The real answer to your question is to leave it off for awhile, then
kick it up and go to the furnace and see
what happens. The furnace should fire, and then a minute or so later
the blower should come on.
Also, it';s not a two stage furnace is it? Don't know if they were
around 12 years ago. But they are common
today. And they can work two ways. First way is with a 2 stage
thermostat, which IMO is the only correct way.
Set up that way, the thermostat calls for either first stage heating,
which is about 70% of full capacity, or full
capacity. The thermostat knows how far the temp needs to go up and
what the recent prior run history has been.
So it can make a good decision on what to do.
The second way, is to just use a regular thermostat. In that case,
the furnace always fires at the low rate first.
You typically can set the number of minutes it will run on low to 5 or
12 minutes. After that, if the thermostat is
still calling for heat, it shifts to full output. The obvious
disadvantage is that is you have it set back to 60, come
home and move it to 68, you're going to be waitingg 12 mins to get to
full output. So, you'd see a longer time
before the temp goes up.