Thanks arkie6. Both are good ideas.

I read the manual that Looby posted, but unfortunately it didnt get me to any definate answers. This thermostat can be used with many different types of systems, so the way you wire it will dictate what stage 1+2 means. Betweent he complexity of the unit wiring and the thermostat, I am not confident that I can figure out if stage 2 is aux, so monitoring the aux at the circuit breaker seems to be the full proof method of figuring out what is going on.

I think i also found the dipswitch to shut down the aux heat, so I can test the temp drop that way as well.

jonny,
if your utility company tracks usage history you can probably determine a base electric use for the home (from transitional seasons). Subtract that from your winter bill to get your heating bill.

I have made a lot of progress over the last few days thanks to some good suggestions.
Yesterday I identified all the circuits for the geo system. The heat pump part of the unit was run to the fuse box separately from the aux heat unit/fan. I was able to use an amp meter to see what current was running on both lines at each displayed stage of the thermostat.

Stage 1 = 6 amp at the heat pump, 1 amp on the fan/aux heat circuit
Stage 1+2 = 6 amp at the heat pump, 1.6 amp on the fan/aux heat circuit
Stage 1+2 (+2 flashing) = 6 amp at the heat pump, 42 amp on the fan/aux heat circuit

So the only difference between the first two was that the fan speeds up. If I had the hot water assist installed on this system, it would have been shut down and used for making hot air.

Aux heat only starts when +2 was flashing. I had always assumed that the flashing was due to the system transitioning between stages, but apparently this really means stage 3.

So at least now I know what the thermostat is telling me =)

My next step is to figure out why the system is using the aux so frequently. The thermostat never budges from 67 degrees, but changes between all three stages frequently. Since my thermostat does not allow me to disable the aux heat, I flipped the dip switch on the geo unit to find out if my house temp would actually go down if aux wasn’t being used. It was about 28 degrees last night and the system did fine.

So now I am thinking that its time to get a thermostat that gives me a little more control over what is going on. I would like to be able to control when stage 3 kicks in. I would prefer to set the system at say 67, and then set stage 3 to begin at 64. Is there a thermostat out there that would be able to do this?

Now we are getting somewhere. Good info.

Maybe your existing thermostat has a time delay built in such that if the temperature setpoint isn't satisfied in so many minutes, it turns on the auxiliary heat.

There are some stats that provide better control of Aux heat use, but I have not found an ideal one yet (IMO). I have the Honeywell Vision Pro 8000 and it has limited control that I make do with, but not ideal. Maybe some of the newer types do. I would like to change, when I find the correct unit that controls venting, humidity, dehum.

For miserly use of Aux heat on a Geo system, I think it needs a long time delay, temp differential settings, and lock outs for temp setback recovery and manual temp change (time limited). This would yield a stat that limits Aux use until its really needed. ie when the geo can't REALLY keep up, time to pull the chute, so to speak.

Most stats seem to care most about user comfort and will call on all sources of heat to satisfy with limited regard to economy. I think this is a big issue in the apparent lack of efficiency reported on Geo systems. A lot of users are oblivious to this issue (IMO).

A sticky added to this forum listing good stats to use and how to set them up properly would save a lot of KW's.

Chris makes good points, and I wish there was a better answer. Over 20 years ago I retrofitted a primitive digital LCD thermostat (from Builders Square, a predecessor to Home Depot, no less) onto my straight cool / oil heat system. That stat let me set spans (how many degrees of droop before system came on) and even logged running hours...what a concept!

It would sure be nice to be able to configure aux heat strips to not come on unless temp was 2-4 degrees below setpoint.

I was poking around the waterfurnace website to look at some newer thermostats and came accross some interesting features on the TP32S. ON page 29 of the PDF available on their website there is a section that speaks to Deadband Settings

"1st stage Deadband - Specifies the minimum temperate difference between the room temperature and the desired setpoint before the first stage of heating or cooling is allowed to turn on. (1-6) degrees For example, if the heat setpoint is 69 and the 1st Stage deadband is set to 2 degrees, the room temperature will need to reach 66 degrees before the heat turns on.

2nd Stage deadband - Specifies the additional minimum temperature difference after the first stage turns on before the second stage is activated (0-10 degrees)

3rd Stage deadband - Specifies the additional minimum temperature difference after the second stage turns on before the third stage is activated (0-10 degrees)"

There are also settings where you can phase the 3rd and second stage back out as the temperature rises.

So for my issue, I would set my thermostat at 68 with a 1 degree deadband for stage 1, then another 2 degrees for stage 2, then another 2 degrees for stage 3(aux heat). My aux would kick in at 63 degrees. Once the temp increased to 65, it would shut off and go back to stage 2, then stage 2 would kick off at 67.

I think all I need to confirm is that aux can be set up as my stage 3.

Posted By jonny4d on 13 Feb 2013 10:30 AM
I would prefer to set the system at say 67, and then set stage 3 to begin at 64.
Is there a thermostat out there that would be able to do this?

Yes, in a klugey sort of way.

Honeywell's "VisionPro IAQ" has an "auxiliary lockout" feature that allows you to
disable auxiliary heat for outdoor temperatures above a user-selected threshold.

Of course, if you put the (optional) "outdoor" temperature probe indoors, you can
disable aux heat for indoor temps above, say, 65F. Unfortunately, the threshold
temperature can be adjusted only in 5 degree steps, up to a maximum of 65F.

Some versions of the (slightly less expensive) "VisionPro 8000" also have this
feature, but with a maximum aux lockout threshold of 60F. As a kluge^2 (yech!),
you could add a fixed resistance in parallel with the thermistor probe -- to tweak
the actual lockout temperature and/or adjust it upwards (above 60F).

Some of the newer Honeywell products (that I haven't researched) might also
have this feature -- or maybe something more direct and less klugey. There's
also a new 3H/2C version of the Nest™ thermostat -- very cool looking, but
rather spendy and possibly too-damned-smart-for-its-own-good.

...shop 'til ya drop,

Looby

I messed up. I actually have the Honeywell VisionPro IAQ. As Looby notes, there is no great (non Klugey) way to control the Aux heat. I like the have the outdoor temp probe outside, so it auto adjusts the humidity with the frost function.

Lukily (or unlucky) I can actually turn my Aux breakers off as my system is a tad too big for my house since I added some air sealing and insulation. Aux never needed yet even down to single digits.

If I were to turn the Aux breakers on, during our 3 degree recovery from night setback, the Aux would come on everyday needlessly. No way to prevent that in my operating scenario with the stat I have.

If I go on vacation, I turn on one of the Aux breakers and set the stat at a fixed set point (no setback). If the compressor were to fail, I would at least have freeze protection. Kinda klugey, but works for me for now.

For Geo users that actually have to have Aux come on during cold snaps, leaving the breaker off is not an optiion. That means that if they like to have a night setback, they will likely use Aux needlessly every morning. At least with my stat and most others for that matter. Total waste of KW's IMO. This issue needs to be raised, again IMO, as lots of cunsumers are quite oblivious to this fact and lots of KWs are being wasted and the GEO name suffers.

I like the deadband options Jonny4 noted, but you need to be aware of nightsetback amounts and deadbands to limit Aux use. Doable, but understanding is needed. Having house mates who love to bump up the stat when no one is looking (as in my friends case, teenage daughter), can really drive up Aux use needlessly. I have yet to find the perfect stat that does everything the IAQ does, but with better Aux control that has better intelligence around when to apply it.

I am starting to work on a controller for my house ventilation that get weather data via the net, and control my vent damper and fresh air fan to limit fresh air intakes during temp extremes (very hot and very cold) and also high outdoor dew points. No stat does that yet. Right now I manually turn it off on from my IAQ. Not the best.

I am in the same boat with the fresh air exchange system. I used to have it plugged into a timer so that It would run 30 min per day, but switched to all manual while we were in single digit temps. I would love to be able to set parameters around when it could run.

I dont set back in the evening. I really want to be able to set and forget, so the deadband option looks like it would work for me.

Is the TP32S made by another company? Or is it exclusing the water furnace?

jonny4d,

We apologize for not responding before now. We have read your comments and according to the information provided, your unit is a single speed unit. We will be more than happy to provide the manuals for your unit; unfortunately, the files are too large to upload to this website. If you will send us a private message with your email address, we will be more than happy to have our Consumer Relations staff send you copies of these manuals.

WaterFurnace International, Inc.