On Saturday, December 9, 2017 at 12:54:21 AM UTC-5, condo owner wrote:
I have a Totaline Model P474-1035 Programmable Thermostat.

This is the link to the owner's manual:

http://www.totaline.com/dl/P474-1035...Thermostat.pdf



page 6 describes how to operate the thermostat MANUALLY:

- the Program Switch is at the "OFF" position.
- the Fan Switch is at the "AUTO" position.
- to set the desired room temperature, use the UP & DOWN buttons.
- to turn the furnace on, move the Mode Switch to "Heat"
- to turn the A/C on, move the Mode Switch to "Cool".

page 17 describes how to adjust the:

- "deadband". What is "deadband"? How many degrees should I set it to?
- cycles per hour. There are 7 values: 2 to 6 degrees; 'd'; and 'dl'. What value should it set it to?

I'm only familiar with deadband as applied to thermostats that automatically
switch from heat to cool on their own. In that case you don't want the heat
and cool fighting with each other, ie if you want it 75F, you don't want
the heat bringing it up to 76, then the cooling taking it down to 75 or 74
over and over. So deadband is where both are off. With a deadband of 4,
the temp would have to go below 73 for it to go into heat mode or above 77
for it to go into cooling mode. Your thermostat doesn't say anything about
auto changeover, so IDK what deadband is in that context. It may be the
range around the desired temp where it fluctuates, ie with a deadband of 4
and a set temp of 75, the heat will come on at 71, go off at 79, but
that seems nuts.

Since you're having problems, I'd set the deadband to 1, the lowest.
The cycles per hour are number of cycles, not degrees. It's how many
times you want the furnace to typically run to maintain the temp.
For example if it's 30F outside, it could run once an hour to keep it
close to 75F or it could run 5 times. The latter will keep fluctuations
smaller, the former is a little more energy efficient. I'd set it to 3.

It's possible that deadband setting is your problem. What was it set to?
If it's high, eg 6, that might be why it's cutting off at 76 instead of 82.