I had a Lenox G61MPV gas furnace installed a month ago along with a
White Rogers 1F80-361 programmable thermostat. At night, I turn the
thermostat down to 58 degrees. In the morning I turn it up to 66.
Throughout the day, the thermostat works well, keeping the room
temperature within about 1 degree of the thermostat setting. But
first thing in the morning, when the furnace has to raise the room
temperature from 58 to 66 degrees, it overshoots the mark by almost 5
degrees before the furnace shuts off. I've tried two different
thermostats and both of them do the same thing. Adjusting the
Temperature Display Adjustment up a few degrees, helps some, but the
room temperature gets too low before the furnace comes on when I do
this. It seems to me that the temperature sensor inside the
thermostat is too slow to adjust to the actual room temperature, so
the furnace stays on too long when it has make up more than 1-2
degrees. My furnace installer just keeps telling me to try another
thermostat, that the problem isn't the furnace. Anyone have any
Not the sensor in the thermostat.
There may be an 'anticipator' adjustment in your thermostat. Check
the paperwork that came with it. It's purpose is to shutdown the
furnace early in "anticipation" of the extra heat.
The model you have *may* come with an adjustment on the control board for
the indoor blower timeing. You might check to see if it's 120 seconds and
can be adjusted down to 90 seconds. Residual heat [in the furance] will
raise the room temperature if the fan is on too long.
Call your installing contractor, and see if he can't adjust the timing under
a warranty call - [or maybe have him come out, check everything over - and
adjust the timing and pay their service call fee.]
The amount of heat extracted from the HX from running the blower an
extra 30 seconds beyond 90 will not raise the room temp enough to
notice, unless the only room with an open register is a closet.
Next time you have a chance, watch the thermostat. It probably has an
indicator on it that indicates when heat is being called for. Try and
notice if when the set temp is being passed, is indicator still
showing call for heat? If it isn't, is the blower fan on the furnace
If the fan still runs after call for heat has stopped, it's a setting
in the furnace, not likely the thermostat.
I seem to recall that some White-Rodgers tstats measure wall
temperature as well as air temperature. The reason is, when the air
temp is changing during a recovery phase, the decision to end the call
for heat (or cool) is based on how much wall temp lags behind the air
temp. For example, starting from 58, the wall is still cold when the
air has warmed to 66. If the tstat shuts the furnace down as soon as
the air reaches 66, the air will rapidly cool off again as heat is
transfered to the wall (and furniture), and the tstat will just have
to call for more heat sooner than later, starting the cycle over
again. Running the furnace longer during recovery gets the walls and
furniture up to temperature faster, which increases comfort, even if
it means overshooting the air temp by a degree or two for a few
Cold air from inside the wall can confuse the tstat into thinking the
wall surface is colder than it is, so don't mount the tstat on an
exterior wall, and make sure the hole in the wall behind the
thermostat is plugged with some insulating material around the wires.
Even if the tstat does not have this additional sensor I spoke of,
these two things are good advice.
Also, consult your owner's manual for information about the "heating
cycle rate" configuration of your W-R 1F80-361. In your case, you may
be better off with the "FA" setting as opposed to the "SL" setting.
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