"Russell Coleman" wrote in message
llsouth.net...
I have a heat pump with aux heat for which I bought a programmable
thermostat. The RTH7400D to be exact

What is the recommendation on setting the temp difference between wake and
sleep times so that I am not going to make the system work to hard and not
get the energy savings that I bought the prog. thermostat for in the
first
place?



The same across the board....
Or, no more than 2F degrees difference between the two.

The most common question asked is : What temp saves me the most money?
The answer is, as low as you can stand it.

With programmable stats, any real savings you think you had, you kill when
the aux heat comes on...if needed for recovery.

Any decent digital stat maintains a 1F differential, so that alone saves you
a ton over a mercury stat.
I said decent...the one you have is a marginal Honeywell....bottom end of
the scale, particularly if you got it at Lowes or Home Depot.