On Mon, 22 Feb 2010 23:07:14 +0000 (UTC), Glenda Copeland
wrote:

How do I adjust a thermostat so that the heat reaches the set temperature?

As to buying a new thermostat, people here are often ready to buy new,
to throw money at a problem.

As to accuracy, what does accuracy matter when people don't know if
they want 74.4 or 74.7, or 75.3? And much moreso is it not important
when they want something around 75 and their husband wants something
around 68. Improved accuracy isn't going to help.

Temperature stabilty is adjustable iirc on the round Honeywell
thermostats. It's called cycle delay or something. But one can't
lower it too much because of the furnace, not because of the
thermostat. It's not good for many furnaces to turn off and then turn
on again when the temp drops 0.1 degrees. This is all the more true
for ACs which need time for pressure to go down where it the
refrigerant is compressed. The thermostat comes set for a reasonable
value and it can be lessened if wanted with most furnaces. If it is
also an AC thermostat, either there are two cycle delay adjustments,
the cycle delay applies to the furnace only, or it can't be lowered
more than is safe for the AC.