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?

My Honeywell round thermostat has a bulb with mercury in it and a coil of
metal that seems to control when it makes electrical contact.

When I set the Honeywell bulb thermostat to 68°F, the heat only gets to
about 58°F. Likewise, when I set the thermostat to 85°F, the heat shuts off
when it reaches about 75°F.

This works fine except my husband keeps yelling at me for setting the
thermostat to 85°.

I'd yell at you too. Who needs 75? Set at 78 and be happy with 68.
Wear a sweater.

I know the simple answer is to change him but why do thermostats have
numbers on them if they're not even close to those numbers?

Is there a way to adjust the temperature? When I pull the round cover off,

Don't pull that cover off. There are electical forces there that will
make your cold cream run.

I see a copper pointer on the bottom with etch marks on the plate below but
that pointer is already all the way to the left and moving it to the right
just seems to make the offset error worse.

In that case you could risk bending the spring or some other part that
is holding the mercury capsule, but two major concerns. 1) Being a
Mercury Capsule, it might head for earth orbit. 2) A good chance
you'll bend it in the wrong direction (it's confusing) or bend it in
the right direction but so much that the offset pointer won't be able
to correct it. And you only get to bend it once or twice and soon it
will break off. Plus you probably need TWO needlenosses to bend it.

What's the procedure to adjust a Honewell round thermostat to reach the set
point before turning off?

You can try to tip the house while holding the thermostat in place.