I take it back. On setting 7, the heat pump comes on but nothing will
trigger the propane. Interestingly, I replaced the OLD thermostat, and the
propane comes on, but NOT the heat pump. What the hell...

John

"Travis Jordan" wrote in message
...
"JohnW" wrote in message
...
The upper floor has a heat pump, presumably in the attic. When we had
the
home inspected I followed the guy into the attic where he pointed out the
unit. My assumption is that this unit handles the heating/cooling of the
2nd story. It has a thermostat in the master bedroom and appears to work
fine when the outside temp is above 20 degrees or so. I'm not worried
about
this system.

A heat pump is just a reverse-cycle air conditioner. In your case it the
air handler is in the attic - but the compressor for the AC / heat pump is
outside.

There are two units outside, one of which appears to be a
dedicated air conditioner and a second unit that's a heat pump.

Nope, they are both condensers, used in conjunction with your inside air
handlers. Likely one or both are also capable of reverse cycle (a heat
pump).

We also
have propane furnace/air handler. These units were controlled by a
mercury-based manual thermostat, but I replaced it with a Honeywell
RTH7400D
programmable thermostat using the same wires (4 wires: g,w,y,r). For
what
it's worth, the propane also provides the heated water and a gas
fireplace.

G - Fan
W - Heat (1st stage)
Y - Cool (1st stage)
R - Power

Here are the questions:

1. Is the heat pump the primary heat source and the propane secondary, or
the opposite? The inspection report calls the propane the primary
source,
but that doesn't seem right, and the seasonal contractor we had inspect
the
unit recently said the propane "appeared" to be the secondary. If it's
not
all that cold outside, the heat pump is on, but not the propane, for
example. Today, at 16 degrees, both units run. And struggles to
maintain
70.

Most commonly the heat pump is primary (1st stage) and the propane would
be
secondary (2nd stage). Are you sure the old thermostat didn't have
another
wire for second stage heat? It could be that the furnance controller
handles calling for the 2nd stage, but that is unusual.

2. The thermostat required a setup before programming the 7 days of the
week. One of the steps was choosing the heating/cooling system. There
are
10 choices:
- heating and cooling (conventional)
- single stage heat pump with no backup or auxilliary heat
- heat only with no fan (conventional)
- heat only with fan (conventional)
- hot water heat only (conventional)
- Cool only (conventional)
- multistage heat pumps
- multistage conventional heating and cooling (2 stages heat and 2
stages
cool: requires w/w2 and y/y2 wires)
- multistage conventional heating and cooling (2 stages of heat and 1
stage
cool)
- multistage conventional heating and cooling (1 stage heat and 2 stages
of
cool)

Right now I have it on the first setting.

Makes sense with only four wires. Are you SURE there wasn't a fifth wire?

3. What are the "stages" regarding heating systems as referred to above?
My
assumption is that a heat pump with emergency/auxilliary heat is a
multistage heat pump (like the one in our attic for the second floor) but
does it also refer to a secondary heating source like natural gas, oil or
propane? If I had a W2 wire I suspect the 9th choice would be the most
appropriate but I just had the 4 wires mentioned above. After calling
Honeywell, the person agreed that the first choice seemed the most
appropriate.

If you have aux / emergency heat strips then it is a 2-stage heat system
(NOT a multistage heat pump, which is a different animal). Of course you
COULD have both a multistage heat pump AND aux / emergency heat, but that
is
uncommon.

4. I have heard twice now that heat pump/propane heat systems work just
fine
if you leave the temperature constant throughout the day/week, but have
trouble with "recovery" when you let it dip in the evening and try to
reheat
in the morning when everyone rises. This seems to be the problem with
these
systems and programmable thermostats. Today I programmed every day and
every "event" to the same temp to see if this pans out over the next few
days.

Ignore what you are hearing. ANY setback saves energy. Google for more
information on this widely misunderstood topic.

I AM going to get the HVAC contractor out here again, at my expense, to
pick
his brain in person, since I wasn't at home when he did the initial
inspection for us. However, any insight to the above beforehand would be
of
great help. Thanks in advance.

Good idea.