"DrMega" wrote in message
oups.com...
Hello group. I had a typical round mercury wall thermostat until a
drunk guy (no, not me :-) shoulder-planted into it and busted off the
dial. I'm thinking of replacing it with a battery-powered digital model
and a preliminary Internet search indicated it should be a pretty
simple two-wire job. But after reading some posts in here I'm a little
more concerned (I'm a fairly new homeowner and not super handy).
Questions a

Don't bother with the round digital t-stats. If you're going to replace the
old analog t-stat, replace it with a -programmable- digital unit. They are
not round but the savings in heat (and cooling if you have a/c) will more
than pay for the unit in one year. They are more expensive ($50-150) but
much more worth it.

They're called programmable because you can program the unit to provide heat
when you are home and not provide heat when you are not home. Some are
"seven-day programmable" meaning all seven days can have a different
program, others are "5-1-1 day" meaning Monday-Friday is the same program
and Saturday and Sunday are separate, and then there's the "5-2 day",
basically one program for the week and another for the weekend.

The wiring is no different, so why bother with a non-programmable digital
t-stat?