Heat Pumps and Electric Heating - Selecting a programmable thermostat for Trane XE1100

Hello - I've got two Trane XE1100 units that are older but running great. The upstairs unit has a Trane Weathertron XT500 programmable thermostat which works great. I'd like to install a programmable thermostat for the downstairs unit, but the XT500 isn't made anymore.

The XE1100 units are two-stage heat pumps. My experience has been that programmable thermostats for those kind of units tend to be pricey. I am thinking of purchasing a Honeywell TH4210D1005 or TH6220D1002 to use with my downstairs unit. I can find the first one for around $50 and he second for around $70. I'm concerned that they are so affordable - are they poor thermostats or did I look at the wrong type for my units?

1. Are either of these thermostats appropriate for my units?
2. If not, can you recommend a programmable thermostat for my trane units?
3. Has the debate regarding the effectiveness of programmable thermostats for 2-stage heat pumps ever been settled? I've heard they work and save money, but I've also heard that they are not effective since the unit has to work harder/less effectively to reheat thereby negating any savings.

Thanks for your patience and assistance!

The TH6220 is a very good thermostat. Recovering from a setback and energizing electric heat strips is not efficient.

There is always the cooling season:)

Thanks, Houston, for the fast reply. If programmable thermostats on two-stage heat pumps do not save money/reduce energy consumption, why are they offered? I can't understand why anyone would use one otherwise. If they really aren't energy and money savers, I may as well leave my old thermostat on the downstairs unit.

I had heard that the programmable thermostats for 2 stage heat pumps actually started to warm the house up several hours before the targeted time, allowing the unit to gradually warm the space and therefore, not utilize auxillary heat. Was I misinformed?

I appreciate you help more than you realize. This is all unfamiliar territory to me.

If you are recovering from a setback of more than a few degrees it will energize your heat strips. I've seen posters complain of this with nicers Honeywell stats than the TH6220.

It would be great if this was addressed in the configuration settings. Pehaps if more posters directed this complaint to the thermostat manufacture...

Programed t-stat has been offred on HP system for many years, and a lot of us don't suggest program set back in the winter months. The savings are not there.

Only t-stat that may work is the Honeywell IAQ t-stat, they use an outdoor sensor to take a temp reading, and able to lock out the electric heat strips.

The Honeyweel Visionpro TH8321 will do something similar. It will not only lock out Aux heat because of setback recovery though...

http://i151.photobucket.com/albums/s160/Houston204/VisionProspecialfunctions.jpg

The problem with the Honeywell configuration is it will only allow you to lockout the aux heat when the outside temperature is 40F or higher! I'm currently trying to figure out how to get this unit to lock out at a more realistic 30F or so, since the heat pump can recover in a reasonable period of time in that environment. Honeywell got so close with this option, only to screw it up with an artificial temperature limit. They'll let some bozo run their inside temperature up to 90F or down to 50F, but put a reasonable limit on this option... NOOOO. :(

Only model Honeywell T-stat allows you to lock out the Aux at a lower temp is the IAQ model.

Bummer! :) I don't want to buy new thermostats, I already have three of these!

Is your system zoned if you had three of the VP.

No, I have three heat pumps, Office, Bedrooms, Main floor. The house is around 5000sq/ft, needs a lot of heat. :)

Wow, okay. Yeah, need the heat. a few bodies don't do the job well!

No problem for the occasional party, then I can turn off the heat. Of course, they all get used for cooling for summer parties! :D Beer 4U2

I'm the original poster, wanting to find a programmable thermostat for my Trane 1000XE units and asking if a programmable thermostat really is effective on heat pumps.

What I am getting from the posts above is that in general, programmable thermostats are NOT effective with heat pumps because the use the auxillary heat when warming up a room after a period of cooler temps (even though they are not supposed to!).

It sounds like the IAQ thermostat has a work around, sort of. It runs about $175. Now I have to figure out how long it would take me to recoup my investment.

Set the therm at a constant 64 or buy the IAQ?

Thoughts?

Here's a link I found discussing the issue:

HEAT PUMP THERMOSTATS: Can programmable thermostats save money when used with ...(Q&A) (http://energyexperts.org/EnergySolutionsDatabase/ResourceDetail.aspx?id=4951)

It mentions that there are programmable thermostats that limit or eliminate auxillary heat during recovery.

More specifically, it mentions White Rodgers Energy Management Recovery thermostats such as the 1F72-151, Honeywell's Adaptive Intelligence Recovery, and Robert Shaws Energy Efficiency Recovery Mode, such as the model 9629 t-stat.

Anybody know anything about those models I mentioned?

Thanks all!

More specifically, it mentions White Rodgers Energy Management Recovery thermostats such as the 1F72-151, Honeywell's Adaptive Intelligence Recovery, and Robert Shaws Energy Efficiency Recovery Mode, such as the model 9629 t-stat.

Anybody know anything about those models I mentioned?

I have not been around the other guys.. I been around mostly Honeywell, and l haven't been exposed to the HP settings on these. As I read else where they say the AIR is going to hold back the Aux heat once the AIR learns the home. If the weather is very cold, and then the the aux will kick in.

That would solve nrusinak's problem and mine as well. :) I haven't found any reference that it actually works that way, I would think that Motorola would put that in the documentation! Where did you see that?

Sorry we kinda' hijacked your thread, I'll go away now. :)